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Harte SJ, Bray DP, Nash-Woolley V, Stevenson PC, Fernández-Grandon GM. Antagonistic and additive effect when combining biopesticides against the fall armyworm, Spodoptera frugiperda. Sci Rep 2024; 14:6029. [PMID: 38472262 PMCID: PMC10933331 DOI: 10.1038/s41598-024-56599-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 03/08/2024] [Indexed: 03/14/2024] Open
Abstract
Fall armyworm, Spodoptera frugiperda (FAW) is a cosmopolitan crop pest species that has recently become established in sub-Saharan Africa and Southeast Asia. Current FAW control is almost entirely dependent on synthetic pesticides. Biopesticides offer a more sustainable alternative but have limitations. For example, pyrethrum is an effective botanical insecticide with low mammalian toxicity but is highly UV labile, resulting in a rapid loss of efficacy in the field. Beauveria bassiana is an entomopathogenic fungus that is more persistent, but there is a time lag of several days before it causes insect mortality and leads to effective control. The combination of these biopesticides could mitigate their drawbacks for FAW control. Here we evaluated the efficacy of pyrethrum and B. bassiana as individual treatments and in combination against 3rd instar FAW. Four different combinations of these two biopesticides were tested, resulting in an antagonistic relationship at the lowest concentrations of B. bassiana and pyrethrum (1 × 104 conidia mL-1 with 25 ppm) and an additive effect for the other 3 combined treatments (1 × 104 conidia mL-1 with 100 ppm and 1 × 105 conidia mL-1 with 25 ppm and 100 ppm pyrethrum). Additionally, a delay in efficacy from B. bassiana was observed when combined with pyrethrum as well as a general inhibition of growth on agar plates. These results appear to show that this particular combination of biopesticides is not universally beneficial or detrimental to pest control strategies and is dependent on the doses of each biopesticide applied. However, the additive effect shown here at specific concentrations does indicate that combining biopesticides could help overcome the challenges of persistence seen in botanical pesticides and the slow establishment of EPF, with the potential to improve effectiveness of biopesticides for IPM.
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Affiliation(s)
- Steven J Harte
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK.
| | - Daniel P Bray
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
| | - Victoria Nash-Woolley
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
- CHAP, Innovation Centre, Innovation Way, Heslington, YO10 5DG, UK
| | - Philip C Stevenson
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
- Royal Botanic Gardens, Kew, Kew Green, Richmond, Surrey, TW9 3AE, UK
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Martel C, Mendieta-Leiva G, Alvarez-Loayza PC, Cano A, Cosio EG, Decock C, Farfan-Rios W, Feeley K, Honorio Coronado E, Huamantupa I, Ibañez AJ, Koepcke de Diller J, León B, Linares-Palomino R, Marcelo Peña JL, Millán B, Moat JF, Pennington RT, Pitman N, Salinas N, Rojas-VeraPinto R, Stevenson PC, Tovar C, Whaley OQ, Young KR. Peru's zoning amendment endangers forests. Science 2024; 383:957. [PMID: 38422129 DOI: 10.1126/science.ado0050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Affiliation(s)
- Carlos Martel
- Royal Botanic Gardens Kew, Surrey TW9 3AB, UK
- Pontificia Universidad Católica del Perú, 15088 Lima, Peru
| | | | | | - Asunción Cano
- Universidad Nacional Mayor de San Marcos, 15081 Lima, Peru
| | - Eric G Cosio
- Pontificia Universidad Católica del Perú, 15088 Lima, Peru
| | - Cony Decock
- Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - William Farfan-Rios
- Department of Biology and Center for Energy, Environment, and Sustainability, Wake Forest University, Winston-Salem, NC 27106, USA
| | - Kenneth Feeley
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
- Fairchild Tropical Botanic Garden, Coral Gables, FL 33156, USA
| | | | - Isau Huamantupa
- Universidad Nacional Amazónica de Madre de Dios, Puerto Maldonado, Peru
| | | | | | - Blanca León
- Geography and the Environment, University of Texas at Austin, Austin, TX 78712, USA
| | - Reynaldo Linares-Palomino
- Center for Conservation Education and Sustainability, Smithsonian's National Zoo & Conservation Biology Institute, Washington, DC 20008, USA
| | | | - Betty Millán
- Universidad Nacional Mayor de San Marcos, 15081 Lima, Peru
| | | | - R Toby Pennington
- Royal Botanic Garden Edinburgh, Edinburgh EH3 5LR, UK
- Department of Geography, University of Exeter, Exeter EX4 4RJ, UK
| | - Nigel Pitman
- Science and Education, The Field Museum, Chicago, IL 60605, USA
| | - Norma Salinas
- Pontificia Universidad Católica del Perú, 15088 Lima, Peru
| | | | - Philip C Stevenson
- Royal Botanic Gardens Kew, Surrey TW9 3AB, UK
- Natural Resources Institute, University of Greenwich, Kent ME4 4TB, UK
| | | | | | - Kenneth R Young
- Geography and the Environment, University of Texas at Austin, Austin, TX 78712, USA
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Burger H, Buttala S, Koch H, Ayasse M, Johnson SD, Stevenson PC. Nectar cardenolides and floral volatiles mediate a specialized wasp pollination system. J Exp Biol 2024; 227:jeb246156. [PMID: 38180227 PMCID: PMC10785657 DOI: 10.1242/jeb.246156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 11/15/2023] [Indexed: 01/06/2024]
Abstract
Specialization in plant pollination systems can arise from traits that function as filters of flower visitors. This may involve chemical traits such as floral volatiles that selectively attract favoured visitors and non-volatile nectar constituents that selectively deter disfavoured visitors through taste or longer-term toxic effects or both. We explored the functions of floral chemical traits in the African milkweed Gomphocarpus physocarpus, which is pollinated almost exclusively by vespid wasps, despite having nectar that is highly accessible to other insects such as honeybees. We demonstrated that the nectar of wasp-pollinated G. physocarpus contains cardenolides that had greater toxic effects on Apis mellifera honeybees than on Vespula germanica wasps, and also reduced feeding rates by honeybees. Behavioural experiments using natural compositions of nectar compounds showed that these interactions are mediated by non-volatile nectar chemistry. We also identified volatile compounds with acetic acid as a main component in the floral scent of G. physocarpus that elicited electrophysiological responses in wasp antennae. Mixtures of these compounds were behaviourally effective for attraction of V. germanica wasps. The results show the importance of both volatile and non-volatile chemical traits as filters that lead to specialization in plant pollination systems.
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Affiliation(s)
- Hannah Burger
- Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Samantha Buttala
- Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Hauke Koch
- Royal Botanic Gardens, Kew,Kew Green, Richmond TW9 3AE, UK
| | - Manfred Ayasse
- Evolutionary Ecology and Conservation Genomics, Ulm University, 89081 Ulm, Germany
| | - Steven D. Johnson
- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Scottsville, Pietermaritzburg 3209, South Africa
| | - Philip C. Stevenson
- Royal Botanic Gardens, Kew,Kew Green, Richmond TW9 3AE, UK
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK
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Zhu Z, Yang C, Keyhani NO, Liu S, Pu H, Jia P, Wu D, Stevenson PC, Fernández-Grandon GM, Pan J, Chen Y, Guan X, Qiu J. Characterization of Terpenoids from the Ambrosia Beetle Symbiont and Laurel Wilt Pathogen Harringtonia lauricola. J Fungi (Basel) 2023; 9:1175. [PMID: 38132776 PMCID: PMC10744799 DOI: 10.3390/jof9121175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/02/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
Little is known concerning terpenoids produced by members of the fungal order Ophiostomales, with the member Harringtonia lauricola having the unique lifestyle of being a beetle symbiont but potentially devastating tree pathogen. Nine known terpenoids, including six labdane diterpenoids (1-6) and three hopane triterpenes (7-9), were isolated from H. lauricola ethyl acetate (EtOAc) extracts for the first time. All compounds were tested for various in vitro bioactivities. Six compounds, 2, 4, 5, 6, 7, and 9, are described functionally. Compounds 2, 4, 5, and 9 expressed potent antiproliferative activity against the MCF-7, HepG2 and A549 cancer cell lines, with half-maximal inhibitory concentrations (IC50s) ~12.54-26.06 μM. Antimicrobial activity bioassays revealed that compounds 4, 5, and 9 exhibited substantial effects against Gram-negative bacteria (Escherichia coli and Ralstonia solanacearum) with minimum inhibitory concentration (MIC) values between 3.13 and 12.50 μg/mL. Little activity was seen towards Gram-positive bacteria for any of the compounds, whereas compounds 2, 4, 7, and 9 expressed antifungal activities (Fusarium oxysporum) with MIC values ranging from 6.25 to 25.00 μg/mL. Compounds 4, 5, and 9 also displayed free radical scavenging abilities towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide (O2-), with IC50 values of compounds 2, 4, and 6 ~3.45-14.04 μg/mL and 22.87-53.31 μg/mL towards DPPH and O2-, respectively. These data provide an insight into the biopharmaceutical potential of terpenoids from this group of fungal insect symbionts and plant pathogens.
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Affiliation(s)
- Zhiqiang Zhu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.Z.); (C.Y.); (S.L.); (H.P.); (Y.C.)
| | - Chenjie Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.Z.); (C.Y.); (S.L.); (H.P.); (Y.C.)
| | - Nemat O. Keyhani
- Department of Biological Sciences, University of Illinois, Chicago, IL 60607, USA;
| | - Sen Liu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.Z.); (C.Y.); (S.L.); (H.P.); (Y.C.)
| | - Huili Pu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.Z.); (C.Y.); (S.L.); (H.P.); (Y.C.)
| | - Peisong Jia
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China;
| | - Dongmei Wu
- Biotechnology Research Institute, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi 832061, China;
| | - Philip C. Stevenson
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; (P.C.S.); (G.M.F.-G.)
| | | | - Jieming Pan
- College of Biology & Pharmacy, Yulin Normal University, Yulin 537000, China;
| | - Yuxi Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.Z.); (C.Y.); (S.L.); (H.P.); (Y.C.)
| | - Xiayu Guan
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Junzhi Qiu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.Z.); (C.Y.); (S.L.); (H.P.); (Y.C.)
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Felix JA, Stevenson PC, Koricheva J. Plant neighbourhood diversity effects on leaf traits: A meta-analysis. Funct Ecol 2023; 37:3150-3163. [PMID: 38505132 PMCID: PMC10946959 DOI: 10.1111/1365-2435.14441] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 09/11/2023] [Indexed: 03/21/2024]
Abstract
Leaf traits often vary with plant neighbourhood composition, which in turn may mediate plant susceptibility to herbivory. However, it is unknown whether there are any common patterns of change in leaf trait expression in response to neighbourhood diversity, and whether these responses confer increased resistance or susceptibility to herbivores.We used meta-analysis to combine data from 43 studies that examined the influence of neighbourhood diversity on eight physical and chemical leaf traits that could affect herbivory. All leaf traits apart from leaf thickness were highly plastic and exhibited significant differences between plant monocultures and species mixtures, but the direction of effect was variable. Leaf toughness was the only trait that displayed a significant decrease with plant diversity, whereas specific leaf area (SLA) and leaf nitrogen were both marginally increased in species mixtures.The magnitude and direction of leaf trait responses to neighbourhood diversity were independent of plant density and phylogenetic diversity, but changes in SLA correlated positively with plant species richness. SLA was also significantly increased in experimental studies, but not in observational studies, while neighbourhoods containing nitrogen-fixers were associated with increased leaf nitrogen and reduced phenolics. When studies on the over-represented species Betula pendula were removed from the analysis, the effect of neighbourhood diversity on leaf toughness became nonsignificant, but phenolics were significantly reduced in diverse neighbourhoods composed of mature trees, and marginally reduced in species mixtures across all studies.Increases in plant neighbourhood diversity are often associated with reductions of herbivory, although in some cases, the reverse occurs, and plants growing in species mixtures are found to suffer greater herbivory than those in monocultures. This study offers a potential explanation for the latter phenomenon, as our results show that leaf trait expression is highly plastic in response to neighbourhood diversity, and in certain cases could lead to increased leaf quality, which in turn could promote greater rates of herbivory. Read the free Plain Language Summary for this article on the Journal blog.
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Affiliation(s)
- Juri A. Felix
- Department of Biological SciencesRoyal Holloway University of LondonEghamUK
- Royal Botanic GardensKewUK
| | | | - Julia Koricheva
- Department of Biological SciencesRoyal Holloway University of LondonEghamUK
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Li J, Liu S, Yang C, Keyhani NO, Pu H, Lin L, Li X, Jia P, Wu D, Pan J, Stevenson PC, Fernández-Grandon GM, Zhang L, Chen Y, Guan X, Qiu J. Characterization of an α-Amylase from the Honeybee Chalk Brood Pathogen Ascosphaera apis. J Fungi (Basel) 2023; 9:1082. [PMID: 37998887 PMCID: PMC10672707 DOI: 10.3390/jof9111082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 11/25/2023] Open
Abstract
The insect pathogenic fungus, Ascosphaera apis, is the causative agent of honeybee chalk brood disease. Amylases are secreted by many plant pathogenic fungi to access host nutrients through the metabolism of starch, and the identification of new amylases can have important biotechnological applications. Production of amylase by A. apis in submerged culture was optimized using the response surface method (RSM). Media composition was modeled using Box-Behnken design (BBD) at three levels of three variables, and the model was experimentally validated to predict amylase activity (R2 = 0.9528). Amylase activity was highest (45.28 ± 1.16 U/mL, mean ± SE) in media composed of 46 g/L maltose and1.51 g/L CaCl2 at a pH of 6.6, where total activity was ~11-fold greater as compared to standard basal media. The enzyme was purified to homogeneity with a 2.5% yield and 14-fold purification. The purified enzyme had a molecular weight of 75 kDa and was thermostable and active in a broad pH range (> 80% activity at a pH range of 7-10), with optimal activity at 55 °C and pH = 7.5. Kinetic analyses revealed a Km of 6.22 mmol/L and a Vmax of 4.21 μmol/mL·min using soluble starch as the substrate. Activity was significantly stimulated by Fe2+ and completely inhibited by Cu2+, Mn2+, and Ba2+ (10 mM). Ethanol and chloroform (10% v/v) also caused significant levels of inhibition. The purified amylase essentially exhibited activity only on hydrolyzed soluble starch, producing mainly glucose and maltose, indicating that it is an endo-amylase (α-amylase). Amylase activity peaked at 99.38 U/mL fermented in a 3.7 L-bioreactor (2.15-fold greater than what was observed in flask cultures). These data provide a strategy for optimizing the production of enzymes from fungi and provide insight into the α-amylase of A. apis.
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Affiliation(s)
- Jincheng Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (J.L.); (S.L.); (C.Y.); (H.P.); (L.L.); (X.L.); (L.Z.); (Y.C.)
| | - Sen Liu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (J.L.); (S.L.); (C.Y.); (H.P.); (L.L.); (X.L.); (L.Z.); (Y.C.)
| | - Chenjie Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (J.L.); (S.L.); (C.Y.); (H.P.); (L.L.); (X.L.); (L.Z.); (Y.C.)
| | - Nemat O. Keyhani
- Department of Biological Sciences, University of Illinois, Chicago, IL 60607, USA;
| | - Huili Pu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (J.L.); (S.L.); (C.Y.); (H.P.); (L.L.); (X.L.); (L.Z.); (Y.C.)
| | - Longbin Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (J.L.); (S.L.); (C.Y.); (H.P.); (L.L.); (X.L.); (L.Z.); (Y.C.)
| | - Xiaoxia Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (J.L.); (S.L.); (C.Y.); (H.P.); (L.L.); (X.L.); (L.Z.); (Y.C.)
| | - Peisong Jia
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China;
| | - Dongmei Wu
- Biotechnology Research Institute, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi 832061, China;
| | - Jieming Pan
- College of Biology & Pharmacy, Yulin Normal University, Yulin 537000, China;
| | - Philip C. Stevenson
- Natural Resources Institute, University of Greenwich, Chatham Maritime ME4 4TB, UK; (P.C.S.); (G.M.F.-G.)
| | | | - Liaoyuan Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (J.L.); (S.L.); (C.Y.); (H.P.); (L.L.); (X.L.); (L.Z.); (Y.C.)
| | - Yuxi Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (J.L.); (S.L.); (C.Y.); (H.P.); (L.L.); (X.L.); (L.Z.); (Y.C.)
| | - Xiayu Guan
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Junzhi Qiu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (J.L.); (S.L.); (C.Y.); (H.P.); (L.L.); (X.L.); (L.Z.); (Y.C.)
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Furse S, Martel C, Yusuf A, Shearman GC, Koch H, Stevenson PC. Sterol composition in plants is specific to pollen, leaf, pollination and pollinator. Phytochemistry 2023; 214:113800. [PMID: 37532086 PMCID: PMC10493607 DOI: 10.1016/j.phytochem.2023.113800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 08/04/2023]
Abstract
Sterols have several roles in planta, including as membrane components. Sterols are also essential nutrients for insects. Based on this, and the different functions of leaves and pollen, we tested the hypotheses that (a) the sterolome is different in leaves and pollen from the same plant, (b) pollens from wind- and insect pollinated plants comprise different sterols, and (c) sterol provision in pollen-rewarding angiosperms differs from nectar-rewarding species. A novel approach to sterolomics was developed, using LCMS to determine the sterol profile of leaf and pollen from a taxonomically diverse range of 36 plant species. Twenty-one sterols were identified unambiguously, with several more identified in trace amounts. C29 sterols dominated the sterolome in most plants. The sterol composition was significantly different in leaf and pollen and their main sterols evolved in different ways. The sterolome of pollen from animal- and wind-pollinated was also significantly different, but not between nectar- and pollen-rewarding species. Our results suggest that the sterol composition in different plant tissues is linked to their biological functions. Sterol composition in pollen might be driven by physical role rather than the nutrient needs of pollinating insects.
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Affiliation(s)
- Samuel Furse
- Royal Botanic Gardens Kew, Kew Road, Richmond, Surrey, TW9 3AB, UK
| | - Carlos Martel
- Royal Botanic Gardens Kew, Kew Road, Richmond, Surrey, TW9 3AB, UK
| | - Abdikarim Yusuf
- Faculty of Health, Science, Social Care and Education, Kingston University, Penrhyn Road, Kingston Upon Thames, Surrey, KT1 2EE, UK
| | - Gemma C Shearman
- Faculty of Health, Science, Social Care and Education, Kingston University, Penrhyn Road, Kingston Upon Thames, Surrey, KT1 2EE, UK
| | - Hauke Koch
- Royal Botanic Gardens Kew, Kew Road, Richmond, Surrey, TW9 3AB, UK
| | - Philip C Stevenson
- Royal Botanic Gardens Kew, Kew Road, Richmond, Surrey, TW9 3AB, UK; Natural Resources Institute, University of Greenwich, Chatham, Kent, ME4 4TB, UK.
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Furse S, Koch H, Wright GA, Stevenson PC. Sterol and lipid metabolism in bees. Metabolomics 2023; 19:78. [PMID: 37644282 PMCID: PMC10465395 DOI: 10.1007/s11306-023-02039-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 07/27/2023] [Indexed: 08/31/2023]
Abstract
BACKGROUND Bees provide essential pollination services for many food crops and are critical in supporting wild plant diversity. However, the dietary landscape of pollen food sources for social and solitary bees has changed because of agricultural intensification and habitat loss. For this reason, understanding the basic nutrient metabolism and meeting the nutritional needs of bees is becoming an urgent requirement for agriculture and conservation. We know that pollen is the principal source of dietary fat and sterols for pollinators, but a precise understanding of what the essential nutrients are and how much is needed is not yet clear. Sterols are key for producing the hormones that control development and may be present in cell membranes, where fatty-acid-containing species are important structural and signalling molecules (phospholipids) or to supply, store and distribute energy (glycerides). AIM OF THE REVIEW In this critical review, we examine the current general understanding of sterol and lipid metabolism of social and solitary bees from a variety of literature sources and discuss implications for bee health. KEY SCIENTIFIC CONCEPTS OF REVIEW We found that while eusocial bees are resilient to some dietary variation in sterol supply the scope for this is limited. The evidence of both de novo lipogenesis and a dietary need for particular fatty acids (FAs) shows that FA metabolism in insects is analogous to mammals but with distinct features. Bees rely on their dietary intake for essential sterols and lipids in a way that is dependent upon pollen availability.
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Affiliation(s)
- Samuel Furse
- Royal Botanic Gardens, Kew Green, Kew, Surrey, TW9 3AB, UK.
| | - Hauke Koch
- Royal Botanic Gardens, Kew Green, Kew, Surrey, TW9 3AB, UK
| | | | - Philip C Stevenson
- Royal Botanic Gardens, Kew Green, Kew, Surrey, TW9 3AB, UK.
- Natural Resources Institute, University of Greenwich, Chatham, Kent, ME4 4TB, UK.
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Fattorini R, Egan PA, Rosindell J, Farrell IW, Stevenson PC. Grayanotoxin I variation across tissues and species of Rhododendron suggest pollinator-herbivore defence trade-offs. Phytochemistry 2023; 212:113707. [PMID: 37149121 DOI: 10.1016/j.phytochem.2023.113707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/25/2023] [Accepted: 05/03/2023] [Indexed: 05/08/2023]
Abstract
Grayanotoxin I (GTX I) is a major toxin in leaves of Rhododendron species, where it provides a defence against insect and vertebrate herbivores. Surprisingly, it is also present in R. ponticum nectar, and this can hold important implications for plant-pollinator mutualisms. However, knowledge of GTX I distributions across the genus Rhododendron and in different plant materials is currently limited, despite the important ecological function of this toxin. Here we characterise GTX I expression in the leaves, petals, and nectar of seven Rhododendron species. Our results indicated interspecific variation in GTX I concentration across all species. GTX I concentrations were consistently higher in leaves compared to petals and nectar. Our findings provide preliminary evidence for phenotypic correlation between GTX I concentrations in defensive tissues (leaves and petals) and floral rewards (nectar), suggesting that Rhododendron species may commonly experience functional trade-offs between herbivore defence and pollinator attraction.
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Affiliation(s)
- Róisín Fattorini
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK; Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK.
| | - Paul A Egan
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO Box 102, Alnarp 23053, Sweden
| | - James Rosindell
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK
| | - Iain W Farrell
- Royal Botanic Gardens, Kew Green, Kew, Richmond, Surrey, TW9 3AE UK
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew Green, Kew, Richmond, Surrey, TW9 3AE UK; Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, ME4 4TB, UK
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Ngoya ZJ, Mkindi AG, Vanek SJ, Ndakidemi PA, Stevenson PC, Belmain SR. Understanding farmer knowledge and site factors in relation to soil-borne pests and pathogens to support agroecological intensification of smallholder bean production systems. Front Sustain Food Syst 2023. [DOI: 10.3389/fsufs.2023.1094739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
Abstract
IntroductionPests and diseases limit common bean (Phaseolus vulgaris) production in intensifying smallholder farming systems of sub-Saharan Africa. Soil-borne pests and diseases (SPD) are particularly challenging for farmers to distinguish and manage in cropping systems that vary in terms of soils, farmer knowledge, and management factors. Few studies have examined soil drivers of SPD in smallholder systems, integrated with farmers' perceptions and management practices.MethodsIn Kilimanjaro, Tanzania, we assessed farmer knowledge and SPD management for common bean alongside soil type and soil quality. Focus group discussions and field survey findings including farmer observations and soil nutrient balances were integrated with soil analyses of farmers' fields. Multiple correspondence analysis (MCA) and principal component analysis (PCA) assessed relationships among farmer demographics, pests and diseases, soil characteristics, and management practices.Results and discussionSurveys revealed that 100% of farmers knew of the bean foliage beetle (Ootheca bennigseni) but few recognized the soilborne pest Ophiomyia spp. or bean fly despite it being more destructive. About a third of farmers knew of root rot diseases caused by Pythium spp. and Fusarium spp. Synthetic pesticides were used by 72% of farmers to control pests, while about half that (37%) used pesticidal plants, particularly Tephrosia vogelii extracts sprayed on foliage. Regarding SPD, 90% of farmers reported that their management practices were ineffective. Meanwhile, synthetic fertilizers were used by nearly all farmers in beans intercropped with maize (Zea mays), whilst very few farmers used manure or compost. Soil available phosphorus was lowbut showed a balance between inputs and outputs regardless of whether fields were owned. Field nitrogen balances were more negative when fields were owned by farmers. An MCA showed that older farmers employed a greater number of pest control practices. The PCA showed that field variability was dominated by soil organic matter, elevation, and soil pH. Higher organic matter levels were also associated with less stunting and wilting of beans observed by farmers. Our results suggest that research and farmer learning about SPD ecology are key gaps, alongside recycling of organic residues to soils. Cost-effective and sustainable practices to manage bean SPDs for smallholders are also needed.
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Figueroa LL, Fowler A, Lopez S, Amaral VE, Koch H, Stevenson PC, Irwin RE, Adler LS. Sunflower spines and beyond: mechanisms and breadth of pollen that reduce gut pathogen infection in the common eastern bumble bee. Funct Ecol 2023. [DOI: 10.1111/1365-2435.14320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Affiliation(s)
- Laura L. Figueroa
- Department of Environmental Conservation University of Massachusetts Amherst Amherst MA 01003 USA
| | - Alison Fowler
- Department of Biology University of Massachusetts Amherst Amherst MA 01003 USA
| | - Stephanie Lopez
- Department of Biology University of Massachusetts Amherst Amherst MA 01003 USA
| | - Victoria E. Amaral
- Department of Applied Ecology North Carolina State University Raleigh NC 27695 USA
| | - Hauke Koch
- Royal Botanic Gardens, Kew Green, Kew, Richmond Surrey TW9 3AE UK
| | - Philip C. Stevenson
- Royal Botanic Gardens, Kew Green, Kew, Richmond Surrey TW9 3AE UK
- Natural Resources Institute University of Greenwich Kent ME4 4TB UK
| | - Rebecca E. Irwin
- Department of Applied Ecology North Carolina State University Raleigh NC 27695 USA
| | - Lynn S. Adler
- Department of Biology University of Massachusetts Amherst Amherst MA 01003 USA
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12
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Ochieng LO, Ogendo JO, Bett PK, Nyaanga JG, Cheruiyot EK, Mulwa RMS, Arnold SEJ, Belmain SR, Stevenson PC. Field margins and botanical insecticides enhance Lablab purpureus yield by reducing aphid pests and supporting natural enemies. J Appl Entomol 2022; 146:838-849. [PMID: 36249719 PMCID: PMC9545213 DOI: 10.1111/jen.13023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 04/21/2022] [Accepted: 04/28/2022] [Indexed: 05/19/2023]
Abstract
Botanical insecticides offer an environmentally benign insect pest management option for field crops with reduced impacts on natural enemies of pests and pollinators while botanically rich field margins can augment their abundance. Here, we evaluated the non-target effects on natural enemies and pest control efficacy on bean aphids in Lablab of three neem- and pyrethrum-based botanical insecticides (Pyerin75EC®, Nimbecidine® and Pyeneem 20EC®) and determine the influence of florally rich field margin vegetation on the recovery of beneficial insects after treatment. The botanical insecticides were applied at the early and late vegetative growth stages. Data were collected on aphids (abundance, damage severity and percent incidence) and natural enemy (abundance) both at pre-spraying and post-spraying alongside Lablab bean yield. The efficacy of botanical insecticides was similar to a synthetic pesticide control and reduced aphid abundance by 88% compared with the untreated control. However, the number of natural enemies was 34% higher in botanical insecticide-treated plots than in plots treated with synthetic insecticide indicating that plant-based treatments were less harmful to beneficial insects. The presence of field margin vegetation increased further the number of parasitic wasps and tachinid flies by 16% and 20%, respectively. This indicated that non-crop habitats can enhance recovery in beneficial insect populations and that botanical insecticides integrate effectively with conservation biological control strategies. Higher grain yields of 2.55-3.04 and 2.95-3.23 t/ha were recorded for both botanical insecticide and synthetic insecticide in the presence of florally enhanced field margins in consecutive cropping seasons. Overall, these data demonstrated that commercial botanical insecticides together with florally rich field margins offer an integrated, environmentally benign and sustainable alternative to synthetic insecticides for insect pest management and increased productivity of the orphan crop legume, Lablab.
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Affiliation(s)
| | - Joshua O. Ogendo
- Department of Crops, Horticulture and SoilsEgerton UniversityNjoroKenya
| | - Philip K. Bett
- Department of Biological SciencesEgerton UniversityNjoroKenya
| | - Jane G. Nyaanga
- Department of Crops, Horticulture and SoilsEgerton UniversityNjoroKenya
| | | | | | - Sarah E. J. Arnold
- Natural Resources InstituteUniversity of GreenwichChatham MaritimeUK
- Nelson Mandela African Institution of Science and TechnologyArushaTanzania
| | - Steven R. Belmain
- Natural Resources InstituteUniversity of GreenwichChatham MaritimeUK
| | - Philip C. Stevenson
- Natural Resources InstituteUniversity of GreenwichChatham MaritimeUK
- Royal Botanic Gardens, Kew, Kew GreenRichmondUK
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Abstract
Evidence from the last few decades indicates that pollinator abundance and diversity are at risk, with many species in decline. Anthropogenic impacts have been the focus of much recent work on the causes of these declines. However, natural processes, from plant chemistry, nutrition and microbial associations to landscape and habitat change, can also profoundly influence pollinator health. Here, we argue that these natural processes require greater attention and may even provide solutions to the deteriorating outlook for pollinators. Existing studies also focus on the decline of individuals and colonies and only occasionally at population levels. In the light of this we redefine pollinator health and argue that a top-down approach is required focusing at the ecological level of communities. We use examples from the primary research, opinion and review articles published in this special issue to illustrate how natural processes influence pollinator health, from community to individuals, and highlight where some of these processes could mitigate the challenges of anthropogenic and natural drivers of change. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
- Philip C Stevenson
- Royal Botanic Gardens, Kew, Kew Green, Richmond, Surrey TW9 3AE, UK.,Natural Resources Institute, University of Greenwich, Kent ME4 4TB, UK
| | - Hauke Koch
- Royal Botanic Gardens, Kew, Kew Green, Richmond, Surrey TW9 3AE, UK
| | - Susan W Nicolson
- Department of Zoology & Entomology, University of Pretoria, Pretoria 0002, South Africa
| | - Mark J F Brown
- Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
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14
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Egan PA, Stevenson PC, Stout JC. Pollinator selection against toxic nectar as a key facilitator of a plant invasion. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210168. [PMID: 35491597 DOI: 10.1098/rstb.2021.0168] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Plant compounds associated with herbivore defence occur widely in floral nectar and can impact pollinator health. We showed previously that Rhododendron ponticum nectar contains grayanotoxin I (GTX I) at concentrations that are lethal or sublethal to honeybees and a solitary bee in the plant's non-native range in Ireland. Here we further examined this conflict and tested the hypotheses that nectar GTX I is subject to negative pollinator-mediated selection in the non-native range, but that phenotypic linkage between GTX I levels in nectar and leaves acts as a constraint on independent evolution. We found that nectar GTX I experienced negative directional selection in the non-native range, in contrast to the native Iberian range, and that the magnitude and frequency of pollinator limitation indicated that selection was pollinator-mediated. Surprisingly, nectar GTX I levels were decoupled from those of leaves in the non-native range, which may have assisted post-invasion evolution of nectar without compromising the anti-herbivore function of GTX I (here demonstrated in bioassays with an ecologically relevant herbivore). Our study emphasizes the centrality of pollinator health as a concept linked to the invasion process, and how post-invasion evolution can be targeted toward minimizing lethal or sub-lethal effects on pollinators. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
- Paul A Egan
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO Box 102, Alnarp 23053, Sweden
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Kew Green, Richmond, Surrey TW9 3AE, UK.,Natural Resources Institute, University of Greenwich, Chatham, Kent ME4 4TB, UK
| | - Jane C Stout
- Department of Botany, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
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Koch H, Welcome V, Kendal-Smith A, Thursfield L, Farrell IW, Langat MK, Brown MJF, Stevenson PC. Host and gut microbiome modulate the antiparasitic activity of nectar metabolites in a bumblebee pollinator. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210162. [PMID: 35491601 PMCID: PMC9058528 DOI: 10.1098/rstb.2021.0162] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Antimicrobial nectar secondary metabolites can support pollinator health by preventing or reducing parasite infections. To better understand the outcome of nectar metabolite-parasite interactions in pollinators, we determined whether the antiparasitic activity was altered through chemical modification by the host or resident microbiome during gut passage. We investigated this interaction with linden (Tilia spp.) and strawberry tree (Arbutus unedo) nectar compounds. Unedone from A. unedo nectar inhibited the common bumblebee gut parasite Crithidia bombi in vitro and in Bombus terrestris gynes. A compound in Tilia nectar, 1-[4-(1-hydroxy-1-methylethyl)-1,3-cyclohexadiene-1-carboxylate]-6-O-β-d-glucopyranosyl-β-d-glucopyranose (tiliaside), showed no inhibition in vitro at naturally occurring concentrations but reduced C. bombi infections of B. terrestris workers. Independent of microbiome status, tiliaside was deglycosylated during gut passage, thereby increasing its antiparasitic activity in the hindgut, the site of C. bombi infections. Conversely, unedone was first glycosylated in the midgut without influence of the microbiome to unedone-8-O-β-d-glucoside, rendering it inactive against C. bombi, but subsequently deglycosylated by the microbiome in the hindgut, restoring its activity. We therefore show that conversion of nectar metabolites by either the host or the microbiome modulates antiparasitic activity of nectar metabolites. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
- Hauke Koch
- Royal Botanic Gardens Kew, Kew Green, Richmond, Surrey TW9 3AE, UK
| | - Vita Welcome
- Royal Botanic Gardens Kew, Kew Green, Richmond, Surrey TW9 3AE, UK.,Imperial College, South Kensington, London SW7 2BX, UK
| | - Amy Kendal-Smith
- Royal Botanic Gardens Kew, Kew Green, Richmond, Surrey TW9 3AE, UK.,Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | - Lucy Thursfield
- Royal Botanic Gardens Kew, Kew Green, Richmond, Surrey TW9 3AE, UK.,John Innes Centre, Norwich, Norfolk NR4 7UH, UK
| | - Iain W Farrell
- Royal Botanic Gardens Kew, Kew Green, Richmond, Surrey TW9 3AE, UK
| | - Moses K Langat
- Royal Botanic Gardens Kew, Kew Green, Richmond, Surrey TW9 3AE, UK
| | - Mark J F Brown
- Centre for Ecology, Evolution and Behaviour, Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Philip C Stevenson
- Royal Botanic Gardens Kew, Kew Green, Richmond, Surrey TW9 3AE, UK.,Natural Resources Institute, University of Greenwich, Greenwich, Kent ME4 4TB, UK
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16
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Furse S, Virtue S, Snowden SG, Vidal-Puig A, Stevenson PC, Chiarugi D, Koulman A. Dietary PUFAs drive diverse system-level changes in lipid metabolism. Mol Metab 2022; 59:101457. [PMID: 35150907 PMCID: PMC8894240 DOI: 10.1016/j.molmet.2022.101457] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE Polyunsaturated fatty acid (PUFA) supplements have been trialled as a treatment for a number of conditions and produced a variety of results. This variety is ascribed to the supplements, that often comprise a mixture of fatty acids, and to different effects in different organs. In this study, we tested the hypothesis that the supplementation of individual PUFAs has system-level effects that are dependent on the molecular structure of the PUFA. METHODS We undertook a network analysis using Lipid Traffic Analysis to identify both local and system-level changes in lipid metabolism using publicly available lipidomics data from a mouse model of supplementation with FA(20:4n-6), FA(20:5n-3), and FA(22:6n-3); arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid, respectively. Lipid Traffic Analysis is a new computational/bioinformatics tool that uses the spatial distribution of lipids to pinpoint changes or differences in control of metabolism, thereby suggesting mechanistic reasons for differences in observed lipid metabolism. RESULTS There was strong evidence for changes to lipid metabolism driven by and dependent on the structure of the supplemented PUFA. Phosphatidylcholine and triglycerides showed a change in the variety more than the total number of variables, whereas phosphatidylethanolamine and phosphatidylinositol showed considerable change in both which variables and the number of them, in a highly PUFA-dependent manner. There was also evidence for changes to the endogenous biosynthesis of fatty acids and to both the elongation and desaturation of fatty acids. CONCLUSIONS These results show that the full biological impact of PUFA supplementation is far wider than any single-organ effect and implies that supplementation and dosing with PUFAs require a system-level assessment.
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Affiliation(s)
- Samuel Furse
- Core Metabolomics and Lipidomics Laboratory, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke's Treatment Centre, Keith Day Road Cambridge, CB2 0QQ, UK; Wellcome-MRC Institute of Metabolic Science and Medical Research Council Metabolic Diseases Unit, University of Cambridge, Addenbrooke's Treatment Centre, Keith Day Road Cambridge, CB2 0QQ, UK; Royal Botanic Gardens, Kew, Kew Green, Richmond, Surrey, TW9 3AE, UK.
| | - Samuel Virtue
- Wellcome-MRC Institute of Metabolic Science and Medical Research Council Metabolic Diseases Unit, University of Cambridge, Addenbrooke's Treatment Centre, Keith Day Road Cambridge, CB2 0QQ, UK
| | - Stuart G Snowden
- Biology Department, Royal Holloway College, University of London, UK; Centro de Investigacion Principe Felipe, 46012 Valencia, Spain
| | - Antonio Vidal-Puig
- Wellcome-MRC Institute of Metabolic Science and Medical Research Council Metabolic Diseases Unit, University of Cambridge, Addenbrooke's Treatment Centre, Keith Day Road Cambridge, CB2 0QQ, UK
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Kew Green, Richmond, Surrey, TW9 3AE, UK; Natural Resources Institute, University of Greenwich, Chatham, Kent ME4 4TB, UK
| | - Davide Chiarugi
- Bioinformatics and Biostatistics Core, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke's Treatment Centre, Keith Day Road Cambridge, CB2 0QQ, UK
| | - Albert Koulman
- Core Metabolomics and Lipidomics Laboratory, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke's Treatment Centre, Keith Day Road Cambridge, CB2 0QQ, UK; Wellcome-MRC Institute of Metabolic Science and Medical Research Council Metabolic Diseases Unit, University of Cambridge, Addenbrooke's Treatment Centre, Keith Day Road Cambridge, CB2 0QQ, UK.
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Fitch G, Figueroa LL, Koch H, Stevenson PC, Adler LS. Understanding effects of floral products on bee parasites: Mechanisms, synergism, and ecological complexity. Int J Parasitol Parasites Wildl 2022; 17:244-256. [PMID: 35299588 PMCID: PMC8920997 DOI: 10.1016/j.ijppaw.2022.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/24/2022] [Accepted: 02/25/2022] [Indexed: 12/27/2022]
Abstract
Floral nectar and pollen commonly contain diverse secondary metabolites. While these compounds are classically thought to play a role in plant defense, recent research indicates that they may also reduce disease in pollinators. Given that parasites have been implicated in ongoing bee declines, this discovery has spurred interest in the potential for 'medicinal' floral products to aid in pollinator conservation efforts. We review the evidence for antiparasitic effects of floral products on bee diseases, emphasizing the importance of investigating the mechanism underlying antiparasitic effects, including direct or host-mediated effects. We discuss the high specificity of antiparasitic effects of even very similar compounds, and highlight the need to consider how nonadditive effects of multiple compounds, and the post-ingestion transformation of metabolites, mediate the disease-reducing capacity of floral products. While the bulk of research on antiparasitic effects of floral products on bee parasites has been conducted in the lab, we review evidence for the impact of such effects in the field, and highlight areas for future research at the floral product-bee disease interface. Such research has great potential both to enhance our understanding of the role of parasites in shaping plant-bee interactions, and the role of plants in determining bee-parasite dynamics. This understanding may in turn reveal new avenues for pollinator conservation.
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Affiliation(s)
- Gordon Fitch
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, 01003, USA
- Corresponding author.
| | - Laura L. Figueroa
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Hauke Koch
- Royal Botanic Gardens, Kew Green, Kew, Richmond, Surrey, TW9 3AE, UK
| | - Philip C. Stevenson
- Royal Botanic Gardens, Kew Green, Kew, Richmond, Surrey, TW9 3AE, UK
- Natural Resources Institute, University of Greenwich, Kent, ME4 4TB, UK
| | - Lynn S. Adler
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, 01003, USA
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Ndakidemi BJ, Mbega ER, Ndakidemi PA, Belmain SR, Arnold SEJ, Woolley VC, Stevenson PC. Field Margin Plants Support Natural Enemies in Sub-Saharan Africa Smallholder Common Bean Farming Systems. Plants (Basel) 2022; 11:898. [PMID: 35406877 PMCID: PMC9002875 DOI: 10.3390/plants11070898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/22/2022] [Accepted: 03/23/2022] [Indexed: 06/14/2023]
Abstract
Flower-rich field margins provide habitats and food resources for natural enemies of pests (NEs), but their potential, particularly in the tropics and on smallholder farms, is poorly understood. We surveyed field margins for plant-NE interactions in bean fields. NEs most often interacted with Bidens pilosa (15.4% of all interactions) and Euphorbia heterophylla (11.3% of all interactions). In cage trials with an aphid-infested bean plant and a single flowering margin plant, the survival of Aphidius colemani, the most abundant parasitoid NE in bean fields, was greater in the presence of Euphorbia heterophylla than Bidens pilosa, Tagetes minuta, and Hyptis suaveolens. UV-fluorescent dye was applied to flowers of specific field margin plant species and NE sampled from within the bean crop and field margins using sweep-netting and pan-traps respectively. Captured insects were examined for the presence of the dye, indicative of a prior visit to the margin. Lady beetles and assassin bugs were most abundant in plots with B. pilosa margins; hoverflies with T. minuta and Parthenium hysterophorus margins; and lacewings with T. minuta and B. pilosa margins. Overall, NE benefitted from field margin plants, and those possessing extra floral nectaries had an added advantage. Field margin plants need careful selection to ensure benefits to different NE groups.
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Affiliation(s)
- Baltazar J. Ndakidemi
- Department of Sustainable Agriculture, The Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, Arusha P.O. Box 447, Tanzania; (E.R.M.); (P.A.N.); (S.E.J.A.)
| | - Ernest R. Mbega
- Department of Sustainable Agriculture, The Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, Arusha P.O. Box 447, Tanzania; (E.R.M.); (P.A.N.); (S.E.J.A.)
| | - Patrick A. Ndakidemi
- Department of Sustainable Agriculture, The Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, Arusha P.O. Box 447, Tanzania; (E.R.M.); (P.A.N.); (S.E.J.A.)
| | - Steven R. Belmain
- Agriculture, Health and Environment Department, Faculty of Engineering & Science, Natural Resources Institute, Medway Campus, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; (S.R.B.); (V.C.W.); (P.C.S.)
| | - Sarah E. J. Arnold
- Department of Sustainable Agriculture, The Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, Arusha P.O. Box 447, Tanzania; (E.R.M.); (P.A.N.); (S.E.J.A.)
- Agriculture, Health and Environment Department, Faculty of Engineering & Science, Natural Resources Institute, Medway Campus, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; (S.R.B.); (V.C.W.); (P.C.S.)
| | - Victoria C. Woolley
- Agriculture, Health and Environment Department, Faculty of Engineering & Science, Natural Resources Institute, Medway Campus, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; (S.R.B.); (V.C.W.); (P.C.S.)
| | - Philip C. Stevenson
- Agriculture, Health and Environment Department, Faculty of Engineering & Science, Natural Resources Institute, Medway Campus, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; (S.R.B.); (V.C.W.); (P.C.S.)
- Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AE, UK
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Woolley VC, Tembo YL, Ndakidemi B, Obanyi JN, Arnold SE, Belmain SR, Ndakidemi PA, Ogendo JO, Stevenson PC. The diversity of aphid parasitoids in East Africa and implications for biological control. Pest Manag Sci 2022; 78:1109-1116. [PMID: 34797017 DOI: 10.1002/ps.6723] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/30/2021] [Accepted: 11/18/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Hymenopteran parasitoids provide key natural pest regulation services and are reared commercially as biological control agents. Therefore, understanding parasitoid community composition in natural populations is important to enable better management for optimized natural pest regulation. We carried out a field study to understand the parasitoid community associated with Aphis fabae on East African smallholder farms. Either common bean (Phaseolus vulgaris) or lablab (Lablab purpureus) sentinel plants were infested with Aphis fabae and deployed in 96 fields across Kenya, Tanzania, and Malawi. RESULTS A total of 463 parasitoids emerged from sentinel plants of which 424 were identified by mitochondrial cytochrome oxidase I (COI) barcoding. Aphidius colemani was abundant in Kenya, Tanzania and Malawi, while Lysiphlebus testaceipes was only present in Malawi. The identity of Aphidius colemani specimens were confirmed by sequencing LWRh and 16S genes and was selected for further genetic and population analyses. A total of 12 Aphidius colemani haplotypes were identified. Of these, nine were from our East African specimens and three from the Barcode of Life Database (BOLD). CONCLUSION Aphidius colemani and Lysiphlebus testaceipes are potential targets for conservation biological control in tropical smallholder agro-ecosystems. We hypothesize that high genetic diversity in East African populations of Aphidius colemani suggests that this species originated in East Africa and has spread globally due to its use as a biological control agent. These East African populations could have potential for use as strains in commercial biological control or to improve existing Aphidius colemani strains by selective breeding.
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Affiliation(s)
- Victoria C Woolley
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, UK
| | - Yolice Lb Tembo
- Lilongwe University of Agriculture and Natural Resources, Bunda College, Lilongwe, Malawi
| | - Baltazar Ndakidemi
- Department of Sustainable Agriculture, Biodiversity and Ecosystems Management, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Janet N Obanyi
- Department of Crops, Horticulture and Soils, Egerton University, Njoro, Kenya
| | - Sarah Ej Arnold
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, UK
- Department of Sustainable Agriculture, Biodiversity and Ecosystems Management, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Steven R Belmain
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, UK
| | - Patrick A Ndakidemi
- Department of Sustainable Agriculture, Biodiversity and Ecosystems Management, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Joshua O Ogendo
- Department of Crops, Horticulture and Soils, Egerton University, Njoro, Kenya
| | - Philip C Stevenson
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, UK
- Royal Botanic Gardens, Kew, Richmond, UK
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20
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Parreño MA, Alaux C, Brunet JL, Buydens L, Filipiak M, Henry M, Keller A, Klein AM, Kuhlmann M, Leroy C, Meeus I, Palmer-Young E, Piot N, Requier F, Ruedenauer F, Smagghe G, Stevenson PC, Leonhardt SD. Critical links between biodiversity and health in wild bee conservation. Trends Ecol Evol 2021; 37:309-321. [PMID: 34955328 DOI: 10.1016/j.tree.2021.11.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 11/24/2021] [Accepted: 11/30/2021] [Indexed: 11/29/2022]
Abstract
Wild bee populations are declining due to human activities, such as land use change, which strongly affect the composition and diversity of available plants and food sources. The chemical composition of food (i.e., nutrition) in turn determines the health, resilience, and fitness of bees. For pollinators, however, the term 'health' is recent and is subject to debate, as is the interaction between nutrition and wild bee health. We define bee health as a multidimensional concept in a novel integrative framework linking bee biological traits (physiology, stoichiometry, and disease) and environmental factors (floral diversity and nutritional landscapes). Linking information on tolerated nutritional niches and health in different bee species will allow us to better predict their distribution and responses to environmental change, and thus support wild pollinator conservation.
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Affiliation(s)
- M A Parreño
- Plant-Insect Interactions, TUM School of Life Science Systems, Technical University of Munich (TUM), Freising, Germany.
| | - C Alaux
- INRAE, Abeilles et Environnement, Avignon, France
| | - J-L Brunet
- INRAE, Abeilles et Environnement, Avignon, France
| | - L Buydens
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - M Filipiak
- Faculty of Biology, Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
| | - M Henry
- INRAE, Abeilles et Environnement, Avignon, France
| | - A Keller
- Center for Computational and Theoretical Biology, and Department of Bioinformatics, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - A-M Klein
- Chair of Nature Conservation and Landscape Ecology, University of Freiburg, Freiburg, Germany
| | - M Kuhlmann
- Zoological Museum of Kiel University, Kiel, Germany
| | - C Leroy
- INRAE, Abeilles et Environnement, Avignon, France
| | - I Meeus
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - E Palmer-Young
- US Department of Agriculture (USDA) Agricultural Research Service Bee Research Laboratory, Beltsville, MD, USA
| | - N Piot
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - F Requier
- Université Paris-Saclay, CNRS, IRD, UMR Évolution, Génomes, Comportement, et Écologie, 91198 Gif-sur-Yvette, France
| | - F Ruedenauer
- Plant-Insect Interactions, TUM School of Life Science Systems, Technical University of Munich (TUM), Freising, Germany
| | - G Smagghe
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - P C Stevenson
- Royal Botanic Gardens, Kew, Surrey TW9 3AE, UK; University of Greenwich, London, UK
| | - S D Leonhardt
- Plant-Insect Interactions, TUM School of Life Science Systems, Technical University of Munich (TUM), Freising, Germany.
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21
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Arnold SEJ, Dudenhöffer JH, Fountain MT, James KL, Hall DR, Farman DI, Wäckers FL, Stevenson PC. Bumble bees show an induced preference for flowers when primed with caffeinated nectar and a target floral odor. Curr Biol 2021; 31:4127-4131.e4. [PMID: 34324835 DOI: 10.1016/j.cub.2021.06.068] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 06/04/2021] [Accepted: 06/24/2021] [Indexed: 12/19/2022]
Abstract
Caffeine is a widely occurring plant defense chemical1,2 that occurs in the nectar of some plants, e.g., Coffea or Citrus spp., where it may influence pollinator behavior to enhance pollination.3,4 Honey bees fed caffeine form longer lasting olfactory memory associations,5 which could give plants with caffeinated nectar an adaptive advantage by inducing more visits to flowers. Caffeinated free-flying bees show enhanced learning performance6 and are more likely to revisit a caffeinated target feeder or artificial flower,7-9 although it is not clear whether improved memory of the target cues or the perception of caffeine as a reward is the cause. Here, we show that inexperienced bumble bees (Bombus terrestris) locate new food sources emitting a learned floral odor more consistently if they have been fed caffeine. In laboratory arena tests, we fed bees a caffeinated food alongside a floral odor blend (priming) and then used robotic experimental flowers10 to disentangle the effects of caffeine improving memory for learned food-associated cues versus caffeine as a reward. Inexperienced bees primed with caffeine made more initial visits to target robotic flowers emitting the target odor compared to control bees or those primed with odor alone. Caffeine-primed bees tended to improve their floral handling time faster. Although the effects of caffeine were short lived, we show that food-locating behaviors in free-flying bumble bees can be enhanced by caffeine provided in the nest. Consequently, there is potential to redesign commercial colonies to enhance bees' forage focus or even bias bees to forage on a specific crop.
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Affiliation(s)
- Sarah E J Arnold
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
| | | | | | - Katie L James
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK
| | - David R Hall
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK
| | - Dudley I Farman
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK
| | | | - Philip C Stevenson
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, UK
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22
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Hien DFDS, Paré PSL, Cooper A, Koama BK, Guissou E, Yaméogo KB, Yerbanga RS, Farrell IW, Ouédraogo JB, Gnankiné O, Ignell R, Cohuet A, Dabiré RK, Stevenson PC, Lefèvre T. Contrasting effects of the alkaloid ricinine on the capacity of Anopheles gambiae and Anopheles coluzzii to transmit Plasmodium falciparum. Parasit Vectors 2021; 14:479. [PMID: 34526119 PMCID: PMC8444468 DOI: 10.1186/s13071-021-04992-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 09/02/2021] [Indexed: 11/18/2022] Open
Abstract
Background Besides feeding on blood, females of the malaria vector Anopheles gambiae sensu lato readily feed on natural sources of plant sugars. The impact of toxic secondary phytochemicals contained in plant-derived sugars on mosquito physiology and the development of Plasmodium parasites remains elusive. The focus of this study was to explore the influence of the alkaloid ricinine, found in the nectar of the castor bean Ricinus communis, on the ability of mosquitoes to transmit Plasmodium falciparum. Methods Females of Anopheles gambiae and its sibling species Anopheles coluzzii were exposed to ricinine through sugar feeding assays to assess the effect of this phytochemical on mosquito survival, level of P. falciparum infection and growth rate of the parasite. Results Ricinine induced a significant reduction in the longevity of both Anopheles species. Ricinine caused acceleration in the parasite growth rate with an earlier invasion of the salivary glands in both species. At a concentration of 0.04 g l−1 in An. coluzzii, ricinine had no effect on mosquito infection, while 0.08 g l−1 ricinine-5% glucose solution induced a 14% increase in An. gambiae infection rate. Conclusions Overall, our findings reveal that consumption of certain nectar phytochemicals can have unexpected and contrasting effects on key phenotypic traits that govern the intensity of malaria transmission. Further studies will be required before concluding on the putative role of ricinine as a novel control agent, including the development of ricinine-based toxic and transmission-blocking sugar baits. Testing other secondary phytochemicals in plant nectar will provide a broader understanding of the impact which plants can have on the transmission of vector-borne diseases. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04992-z.
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Affiliation(s)
- Domonbabele F D S Hien
- Institut de Recherche en Sciences de La Santé (IRSS), Bobo Dioulasso, Burkina Faso. .,Laboratoire Mixte International Sur Les Vecteurs (LAMIVECT), Bobo Dioulasso, Burkina Faso. .,MIVEGEC, Université de Montpellier, IRD, CNRS, Montpellier, France.
| | - Prisca S L Paré
- Institut de Recherche en Sciences de La Santé (IRSS), Bobo Dioulasso, Burkina Faso.,MIVEGEC, Université de Montpellier, IRD, CNRS, Montpellier, France.,Université Joseph KI-ZERBO, Ougadougou, Burkina Faso
| | - Amanda Cooper
- Royal Botanic Gardens, Kew, Surrey, Richmond, TW9 3AE, UK
| | - Benjamin K Koama
- Institut de Recherche en Sciences de La Santé (IRSS), Bobo Dioulasso, Burkina Faso.,Institut Des Sciences Et Techniques, Université Nazi Boni, Bobo-Dioulasso, Burkina Faso
| | - Edwige Guissou
- Institut de Recherche en Sciences de La Santé (IRSS), Bobo Dioulasso, Burkina Faso.,Laboratoire Mixte International Sur Les Vecteurs (LAMIVECT), Bobo Dioulasso, Burkina Faso.,MIVEGEC, Université de Montpellier, IRD, CNRS, Montpellier, France
| | - Koudraogo B Yaméogo
- Institut de Recherche en Sciences de La Santé (IRSS), Bobo Dioulasso, Burkina Faso.,Laboratoire Mixte International Sur Les Vecteurs (LAMIVECT), Bobo Dioulasso, Burkina Faso
| | - Rakiswendé S Yerbanga
- Institut de Recherche en Sciences de La Santé (IRSS), Bobo Dioulasso, Burkina Faso.,Laboratoire Mixte International Sur Les Vecteurs (LAMIVECT), Bobo Dioulasso, Burkina Faso
| | - Iain W Farrell
- Royal Botanic Gardens, Kew, Surrey, Richmond, TW9 3AE, UK
| | - Jean B Ouédraogo
- Institut de Recherche en Sciences de La Santé (IRSS), Bobo Dioulasso, Burkina Faso
| | | | - Rickard Ignell
- Department of Plant Protection Biology, Unit of Chemical Ecology, Disease Vector Group, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anna Cohuet
- Laboratoire Mixte International Sur Les Vecteurs (LAMIVECT), Bobo Dioulasso, Burkina Faso.,MIVEGEC, Université de Montpellier, IRD, CNRS, Montpellier, France
| | - Roch K Dabiré
- Institut de Recherche en Sciences de La Santé (IRSS), Bobo Dioulasso, Burkina Faso.,Laboratoire Mixte International Sur Les Vecteurs (LAMIVECT), Bobo Dioulasso, Burkina Faso
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Surrey, Richmond, TW9 3AE, UK.,Natural Resources Institute, University of Greenwich, Kent, ME4 4TB, UK
| | - Thierry Lefèvre
- Laboratoire Mixte International Sur Les Vecteurs (LAMIVECT), Bobo Dioulasso, Burkina Faso.,MIVEGEC, Université de Montpellier, IRD, CNRS, Montpellier, France.,Centre de Recherche en Écologie Et Évolution de La Santé (CREES), Montpellier, France
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23
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Folly AJ, Koch H, Farrell IW, Stevenson PC, Brown MJF. Agri-environment scheme nectar chemistry can suppress the social epidemiology of parasites in an important pollinator. Proc Biol Sci 2021; 288:20210363. [PMID: 34034519 PMCID: PMC8150011 DOI: 10.1098/rspb.2021.0363] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/05/2021] [Indexed: 12/20/2022] Open
Abstract
Emergent infectious diseases are one of the main drivers of species loss. Emergent infection with the microsporidian Nosema bombi has been implicated in the population and range declines of a suite of North American bumblebees, a group of important pollinators. Previous work has shown that phytochemicals found in pollen and nectar can negatively impact parasites in individuals, but how this relates to social epidemiology and by extension whether plants can be effectively used as pollinator disease management strategies remains unexplored. Here, we undertook a comprehensive screen of UK agri-environment scheme (AES) plants, a programme designed to benefit pollinators and wider biodiversity in agricultural settings, for phytochemicals in pollen and nectar using liquid chromatography and mass spectrometry. Caffeine, which occurs across a range of plant families, was identified in the nectar of sainfoin (Onobrychis viciifolia), a component of UK AES and a major global crop. We showed that caffeine significantly reduces N. bombi infection intensity, both prophylactically and therapeutically, in individual bumblebees (Bombus terrestris), and, for the first time, that such effects impact social epidemiology, with colonies reared from wild-caught queens having both lower prevalence and intensity of infection. Furthermore, infection prevalence was lower in foraging bumblebees from caffeine-treated colonies, suggesting a likely reduction in population-level transmission. Combined, these results show that N. bombi is less likely to be transmitted intracolonially when bumblebees consume naturally available caffeine, and that this may in turn reduce environmental prevalence. Consequently, our results demonstrate that floral phytochemicals at ecologically relevant concentrations can impact pollinator disease epidemiology and that planting strategies that increase floral abundance to support biodiversity could be co-opted as disease management tools.
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Affiliation(s)
- Arran J. Folly
- Centre for Ecology, Evolution and Behaviour, Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, UK
| | | | | | - Philip C. Stevenson
- Royal Botanic Gardens, Kew, UK
- Natural Resources Institute, University of Greenwich, Kent, UK
| | - Mark J. F. Brown
- Centre for Ecology, Evolution and Behaviour, Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, UK
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24
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Zu P, Koch H, Schwery O, Pironon S, Phillips C, Ondo I, Farrell IW, Nes WD, Moore E, Wright GA, Farman DI, Stevenson PC. Pollen sterols are associated with phylogeny and environment but not with pollinator guilds. New Phytol 2021; 230:1169-1184. [PMID: 33484583 PMCID: PMC8653887 DOI: 10.1111/nph.17227] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 01/14/2021] [Indexed: 06/01/2023]
Abstract
Phytosterols are primary plant metabolites that have fundamental structural and regulatory functions. They are also essential nutrients for phytophagous insects, including pollinators, that cannot synthesize sterols. Despite the well-described composition and diversity in vegetative plant tissues, few studies have examined phytosterol diversity in pollen. We quantified 25 pollen phytosterols in 122 plant species (105 genera, 51 families) to determine their composition and diversity across plant taxa. We searched literature and databases for plant phylogeny, environmental conditions, and pollinator guilds of the species to examine the relationships with pollen sterols. 24-methylenecholesterol, sitosterol and isofucosterol were the most common and abundant pollen sterols. We found phylogenetic clustering of twelve individual sterols, total sterol content and sterol diversity, and of sterol groupings that reflect their underlying biosynthesis pathway (C-24 alkylation, ring B desaturation). Plants originating in tropical-like climates (higher mean annual temperature, lower temperature seasonality, higher precipitation in wettest quarter) were more likely to record higher pollen sterol content. However, pollen sterol composition and content showed no clear relationship with pollinator guilds. Our study is the first to show that pollen sterol diversity is phylogenetically clustered and that pollen sterol content may adapt to environmental conditions.
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Affiliation(s)
- Pengjuan Zu
- Royal Botanic GardensKew, Natural Capital and Plant Health DepartmentRichmondSurreyTW9 3ABUK
- Department Fish Ecology and EvolutionSwiss Federal Institute of Aquatic Science and TechnologySeestrasse 79KastanienbaumCH‐6047Switzerland
| | - Hauke Koch
- Royal Botanic GardensKew, Natural Capital and Plant Health DepartmentRichmondSurreyTW9 3ABUK
| | - Orlando Schwery
- New Mexico Consortium4200 W. Jemez Rd, Suite 301Los AlamosNM87544USA
| | - Samuel Pironon
- Royal Botanic GardensKew, Biodiversity Informatics and Spatial Analysis DepartmentRichmondSurreyTW9 3ABUK
| | - Charlotte Phillips
- Royal Botanic GardensKew, Biodiversity Informatics and Spatial Analysis DepartmentRichmondSurreyTW9 3ABUK
- Royal Botanic GardensKew, Conservation Science DepartmentWakehurst PlaceArdinglyWest SussexRH17 6TNUK
| | - Ian Ondo
- Royal Botanic GardensKew, Biodiversity Informatics and Spatial Analysis DepartmentRichmondSurreyTW9 3ABUK
| | - Iain W. Farrell
- Royal Botanic GardensKew, Natural Capital and Plant Health DepartmentRichmondSurreyTW9 3ABUK
| | - W. David Nes
- Department of Chemistry & BiochemistryTexas Tech UniversityLubbockTX79424USA
| | - Elynor Moore
- Department of ZoologyUniversity of Oxford11a Mansfield RoadOxfordOX1 3SZUK
| | | | - Dudley I. Farman
- Natural Resources InstituteUniversity of GreenwichChatham, KentME4 4TBUK
| | - Philip C. Stevenson
- Royal Botanic GardensKew, Natural Capital and Plant Health DepartmentRichmondSurreyTW9 3ABUK
- Natural Resources InstituteUniversity of GreenwichChatham, KentME4 4TBUK
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25
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Elisante F, Ndakidemi P, Arnold SEJ, Belmain SR, Gurr GM, Darbyshire I, Xie G, Stevenson PC. Insect pollination is important in a smallholder bean farming system. PeerJ 2020; 8:e10102. [PMID: 33150065 PMCID: PMC7583606 DOI: 10.7717/peerj.10102] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 09/14/2020] [Indexed: 11/20/2022] Open
Abstract
Background Many crops are dependent on pollination by insects. Habitat management in agricultural landscapes can support pollinator services and even augment crop production. Common bean (Phaseolus vulgaris L.) is an important legume for the livelihoods of smallholder farmers in many low-income countries, particularly so in East Africa. While this crop is autogamous, it is frequently visited by pollinating insects that could improve yields. However, the value of pollination services to common beans (Kariasii) yield is not known. Methods We carried out pollinator-exclusion experiments to determine the contribution of insect pollinators to bean yields. We also carried out a fluorescent-dye experiment to evaluate the role of field margins as refuge for flower-visitors. Results Significantly higher yields, based on pods per plant and seeds per pod, were recorded from open-pollinated and hand-pollinated flowers compared to plants from which pollinators had been excluded indicating that flower visitors contribute significantly to bean yields. Similarly, open and hand-pollinated plants recorded the highest mean seed weight. Extrapolation of yield data to field scale indicated a potential increase per hectare from 681 kg in self-pollinated beans to 1,478 kg in open-pollinated beans indicating that flower visitors contributed significantly to crop yield of beans. Our marking study indicated that flower-visiting insects including bees, flies and lepidopterans moved from the field margin flowers into the bean crop. Overall, these results show that insect pollinators are important for optimising bean yields and an important food security consideration on smallholder farms. Field margin vegetation also provides habitat for flower-visiting insects that pollinate beans. Hence, non-crop habitats merit further research focusing on establishing which field margin species are most important and their capacity to support other ecosystem services such as natural pest regulation or even pests.
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Affiliation(s)
- Filemon Elisante
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Patrick Ndakidemi
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Sarah E J Arnold
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.,Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, United Kingdom
| | - Steven R Belmain
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, United Kingdom
| | - Geoff M Gurr
- School of Agricultural and Wine Sciences, Charles Sturt University, Orange, Australia
| | - Iain Darbyshire
- Royal Botanic Gardens, Kew, Richmond, Surrey, United Kingdom
| | - Gang Xie
- Quantitative Consulting Unit, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Philip C Stevenson
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, United Kingdom.,Royal Botanic Gardens, Kew, Richmond, Surrey, United Kingdom
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26
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Aguirre LA, Davis JK, Stevenson PC, Adler LS. Herbivory and Time Since Flowering Shape Floral Rewards and Pollinator-Pathogen Interactions. J Chem Ecol 2020; 46:978-986. [PMID: 32876829 DOI: 10.1007/s10886-020-01213-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/07/2020] [Accepted: 08/24/2020] [Indexed: 10/23/2022]
Abstract
Herbivory can induce chemical changes throughout plant tissues including flowers, which could affect pollinator-pathogen interactions. Pollen is highly defended compared to nectar, but no study has examined whether herbivory affects pollen chemistry. We assessed the effects of leaf herbivory on nectar and pollen alkaloids in Nicotiana tabacum, and how herbivory-induced changes in nectar and pollen affect pollinator-pathogen interactions. We damaged leaves of Nicotiana tabacum using the specialist herbivore Manduca sexta and compared nicotine and anabasine concentrations in nectar and pollen. We then pooled nectar and pollen by collection periods (within and after one month of flowering), fed them in separate experiments to bumble bees (Bombus impatiens) infected with the gut pathogen Crithidia bombi, and assessed infections after seven days. We did not detect alkaloids in nectar, and leaf damage did not alter the effect of nectar on Crithidia counts. In pollen, herbivory induced higher concentrations of anabasine but not nicotine, and alkaloid concentrations rose and then fell as a function of days since flowering. Bees fed pollen from damaged plants had Crithidia counts 15 times higher than bees fed pollen from undamaged plants, but only when pollen was collected after one month of flowering, indicating that both damage and time since flowering affected interaction outcomes. Within undamaged treatments, bees fed late-collected pollen had Crithidia counts 10 times lower than bees fed early-collected pollen, also indicating the importance of time since flowering. Our results emphasize the role of herbivores in shaping pollen chemistry, with consequences for interactions between pollinators and their pathogens.
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Affiliation(s)
- Luis A Aguirre
- Department of Biology, University of Massachusetts, Amherst, MA, 01003, USA.
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA, 01003, USA.
| | - Julie K Davis
- Department of Entomology, Cornell University, Ithaca, NY, 14850, USA
| | - Philip C Stevenson
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Surrey, TW9 3AB, UK
- Natural Resources Institute, University of Greenwich, Chatham, Kent, ME4 4TB, UK
| | - Lynn S Adler
- Department of Biology, University of Massachusetts, Amherst, MA, 01003, USA
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27
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Zu P, Boege K, Del-Val E, Schuman MC, Stevenson PC, Zaldivar-Riverón A, Saavedra S. Information arms race explains plant-herbivore chemical communication in ecological communities. Science 2020; 368:1377-1381. [PMID: 32554595 DOI: 10.1126/science.aba2965] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/25/2020] [Accepted: 04/15/2020] [Indexed: 01/10/2023]
Abstract
Plants emit an extraordinary diversity of chemicals that provide information about their identity and mediate their interactions with insects. However, most studies of this have focused on a few model species in controlled environments, limiting our capacity to understand plant-insect chemical communication in ecological communities. Here, by integrating information theory with ecological and evolutionary theories, we show that a stable information structure of plant volatile organic compounds (VOCs) can emerge from a conflicting information process between plants and herbivores. We corroborate this information "arms race" theory with field data recording plant-VOC associations and plant-herbivore interactions in a tropical dry forest. We reveal that plant VOC redundancy and herbivore specialization can be explained by a conflicting information transfer. Information-based communication approaches can increase our understanding of species interactions across trophic levels.
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Affiliation(s)
- Pengjuan Zu
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Karina Boege
- Instituto de Ecología, Universidad Nacional Autónoma de México, 04510 Ciudad de México, México
| | - Ek Del-Val
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Unidad Morelia Universidad Nacional Autónoma de México, 58190 Morelia, Michoacán, México
| | - Meredith C Schuman
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, DE-07745, Germany.,Departments of Chemistry and Geography, University of Zurich, CH-8057 Zurich, Switzerland
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew Richmond, Surrey TW9 3AB, UK.,Natural Resources Institute, University of Greenwich, Chatham, Kent ME4 4TB, UK
| | | | - Serguei Saavedra
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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28
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Folly AJ, Stevenson PC, Brown MJF. Age-related pharmacodynamics in a bumblebee-microsporidian system mirror similar patterns in vertebrates. ACTA ACUST UNITED AC 2020; 223:jeb.217828. [PMID: 32107305 DOI: 10.1242/jeb.217828] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/23/2020] [Indexed: 12/27/2022]
Abstract
Immune systems provide a key defence against diseases. However, they are not a panacea and so both vertebrates and invertebrates co-opt naturally occurring bioactive compounds to treat themselves against parasites and pathogens. In vertebrates, this co-option is complex, with pharmacodynamics leading to differential effects of treatment at different life stages, which may reflect age-linked differences in the immune system. However, our understanding of pharmacodynamics in invertebrates is almost non-existent. Critically, this knowledge may elucidate broad parallels across animals in regard to the requirement for the co-option of bioactive compounds to ameliorate disease. Here, we used biochanin A, an isoflavone found in the pollen of red clover (Trifolium pratense), to therapeutically treat Nosema bombi (Microsporidia) infection in bumblebee (Bombus terrestris) larvae and adults, and thus examine age-linked pharmacodynamics in an invertebrate. Therapeutic treatment of larvae with biochanin A did not reduce the infection intensity of N. bombi in adults. In contrast, therapeutic treatment of adults did reduce the infection intensity of N. bombi This transition in parasite resistance to bioactive compounds mirrors the age-linked pharmacodynamics of vertebrates. Understanding how different life-history stages respond to therapeutic compounds will provide novel insights into the evolution of foraging and self-medication behaviour in natural systems more broadly.
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Affiliation(s)
- Arran J Folly
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EY, UK .,Animal and Plant Health Agency, Addlestone, Surrey KT15 3NB, UK
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Richmond, London TW9 3AE, UK.,Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK
| | - Mark J F Brown
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EY, UK
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Adler LS, Fowler AE, Malfi RL, Anderson PR, Coppinger LM, Deneen PM, Lopez S, Irwin RE, Farrell IW, Stevenson PC. Assessing Chemical Mechanisms Underlying the Effects of Sunflower Pollen on a Gut Pathogen in Bumble Bees. J Chem Ecol 2020; 46:649-658. [DOI: 10.1007/s10886-020-01168-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 02/04/2020] [Accepted: 03/06/2020] [Indexed: 12/16/2022]
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30
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Fernández-Grandon GM, Harte SJ, Ewany J, Bray D, Stevenson PC. Additive Effect of Botanical Insecticide and Entomopathogenic Fungi on Pest Mortality and the Behavioral Response of Its Natural Enemy. Plants (Basel) 2020; 9:plants9020173. [PMID: 32024119 PMCID: PMC7076379 DOI: 10.3390/plants9020173] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 01/27/2020] [Accepted: 01/29/2020] [Indexed: 11/16/2022]
Abstract
Sustainable agricultural intensification employs alternatives to synthetic insecticides for pest management, but these are not always a direct replacement. Botanical insecticides, for example, have rapid knockdown but are highly labile and while biological pesticides are more persistent, they are slow acting. To mitigate these shortcomings, we combined the entomopathogenic fungus (EPF) Metarhizium anisopliae with pyrethrum and evaluated their efficacy against the bean aphid, Aphis fabae. To ascertain higher trophic effects, we presented these treatments to the parasitoid, Aphidius colemani, on an aphid infested plant in a Y-tube olfactometer and measured their preferences. Aphid mortality was significantly higher than controls when exposed to EPF or pyrethrum but was greater still when exposed to a combination of both treatments, indicating an additive effect. This highlights the potential for applications of pyrethrum at lower doses, or the use of less refined products with lower production costs to achieve control. While parasitoids were deterred by aphid infested plants treated with EPF, no preference was observed with the combination pesticide, which provides insight into the importance that both application technique and timing may play in the success of this new technology. These results indicate the potential for biorational pesticides that combine botanicals with EPF.
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Affiliation(s)
| | - Steven J Harte
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
| | - Jaspher Ewany
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
| | - Daniel Bray
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
| | - Philip C Stevenson
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
- Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, UK
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31
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Fernández-Grandon GM, Harte SJ, Ewany J, Bray D, Stevenson PC. Additive Effect of Botanical Insecticide and Entomopathogenic Fungi on Pest Mortality and the Behavioral Response of Its Natural Enemy. Plants (Basel) 2020. [PMID: 32024119 DOI: 10.3390/plants9020173www.mdpi.com/journal/plants] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Sustainable agricultural intensification employs alternatives to synthetic insecticides for pest management, but these are not always a direct replacement. Botanical insecticides, for example, have rapid knockdown but are highly labile and while biological pesticides are more persistent, they are slow acting. To mitigate these shortcomings, we combined the entomopathogenic fungus (EPF) Metarhizium anisopliae with pyrethrum and evaluated their efficacy against the bean aphid, Aphis fabae. To ascertain higher trophic effects, we presented these treatments to the parasitoid, Aphidius colemani, on an aphid infested plant in a Y-tube olfactometer and measured their preferences. Aphid mortality was significantly higher than controls when exposed to EPF or pyrethrum but was greater still when exposed to a combination of both treatments, indicating an additive effect. This highlights the potential for applications of pyrethrum at lower doses, or the use of less refined products with lower production costs to achieve control. While parasitoids were deterred by aphid infested plants treated with EPF, no preference was observed with the combination pesticide, which provides insight into the importance that both application technique and timing may play in the success of this new technology. These results indicate the potential for biorational pesticides that combine botanicals with EPF.
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Affiliation(s)
| | - Steven J Harte
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
| | - Jaspher Ewany
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
| | - Daniel Bray
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
| | - Philip C Stevenson
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
- Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, UK
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32
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Mkenda PA, Ndakidemi PA, Mbega E, Stevenson PC, Arnold SEJ, Gurr GM, Belmain SR. Multiple ecosystem services from field margin vegetation for ecological sustainability in agriculture: scientific evidence and knowledge gaps. PeerJ 2019; 7:e8091. [PMID: 31799074 PMCID: PMC6885351 DOI: 10.7717/peerj.8091] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 10/23/2019] [Indexed: 01/12/2023] Open
Abstract
Background Field margin and non-crop vegetation in agricultural systems are potential ecosystem services providers because they offer semi-natural habitats for both below and above ground animal groups such as soil organisms, small mammals, birds and arthropods that are service supplying units. They are considered as a target area for enhancing farm biodiversity. Methodology To explore the multiple potential benefits of these semi-natural habitats and to identify research trends and knowledge gaps globally, a review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 235 publications from the year 2000 to 2016 in the Scopus and Web of Science databases were reviewed. Results The literature showed an increasing trend in the number of published articles over time with European studies leading in the proportion of studies conducted, followed by North America, Asia, South America, Africa and Australia. Several functional groups of organisms were studied from field margin and non-crop vegetation around agricultural lands including natural enemies (37%), insect pests (22%), birds (17%), pollinators (16%), soil macro fauna (4%) and small mammals (4%). Ecosystem services derived from the field margin included natural pest regulation, pollination, nutrient cycling and reduced offsite erosion. Some field margin plants were reported to host detrimental crop pests, a major ecosystem dis-service, potentially leading to increased pest infestation in the field. Conclusion The majority of studies revealed the importance of field margin and non-crop vegetation around arable fields in enhancing ecosystem biodiversity. Promotion of field margin plants that selectively enhance the population of beneficial organisms would support sustainable food security rather than simply boosting plant diversity. Our analyses also highlight that agro-ecological studies remain largely overlooked in some regions.
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Affiliation(s)
- Prisila A Mkenda
- Department of Sustainable Agriculture, Biodiversity and Ecosystems Management, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.,School of Agricultural and Wine Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia.,Department of Biosciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Patrick A Ndakidemi
- Department of Sustainable Agriculture, Biodiversity and Ecosystems Management, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Ernest Mbega
- Department of Sustainable Agriculture, Biodiversity and Ecosystems Management, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Philip C Stevenson
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, UK.,Royal Botanic Gardens, Kew, Richmond, Surrey, UK
| | - Sarah E J Arnold
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, UK
| | - Geoff M Gurr
- School of Agricultural and Wine Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia.,Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Steven R Belmain
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, UK
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33
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Arnold SEJ, Forbes SJ, Hall DR, Farman DI, Bridgemohan P, Spinelli GR, Bray DP, Perry GB, Grey L, Belmain SR, Stevenson PC. Floral Odors and the Interaction between Pollinating Ceratopogonid Midges and Cacao. J Chem Ecol 2019; 45:869-878. [PMID: 31741191 DOI: 10.1007/s10886-019-01118-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/01/2019] [Accepted: 09/10/2019] [Indexed: 11/25/2022]
Abstract
Most plant species depend upon insect pollination services, including many cash and subsistence crops. Plants compete to attract those insects using visual cues and floral odor which pollinators associate with a reward. The cacao tree, Theobroma cacao, has a highly specialized floral morphology permitting pollination primarily by Ceratopogonid midges. However, these insects do not depend upon cacao flowers for their life cycle, and can use other sugar sources. To understand how floral cues mediate pollination in cacao we developed a method for rearing Ceratopogonidae through several complete lifecycles to provide material for bioassays. We carried out collection and analysis of cacao floral volatiles, and identified a bouquet made up exclusively of saturated and unsaturated, straight-chain hydrocarbons, which is unusual among floral odors. The most abundant components were tridecane, pentadecane, (Z)-7-pentadecene and (Z)-8-heptadecene with a heptadecadiene and heptadecatriene as minor components. We presented adult midges, Forcipomyia sp. (subgen. Forcipomyia), Culicoides paraensis and Dasyhelea borgmeieri, with natural and synthetic cacao flower odors in choice assays. Midges showed weak attraction to the complete natural floral odor in the assay, with no significant evidence of interspecific differences. This suggests that cacao floral volatiles play a role in pollinator behavior. Midges were not attracted to a synthetic blend of the above four major components of cacao flower odor, indicating that a more complete blend is required for attraction. Our findings indicate that cacao pollination is likely facilitated by the volatile blend released by flowers, and that the system involves a generalized odor response common to different species of Ceratopogonidae.
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Affiliation(s)
- Sarah E J Arnold
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK.
| | - Samantha J Forbes
- Centre for Tropical Environmental and Sustainability Science, College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
| | - David R Hall
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
| | - Dudley I Farman
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
| | - Puran Bridgemohan
- Biosciences, Agriculture and Food Technologies, University of Trinidad and Tobago, Caroni North Bank Road, Arima, Trinidad and Tobago
| | - Gustavo R Spinelli
- División Entomología, Museo de La Plata, Paseo del Bosque s/n, 1900, La Plata, Argentina
| | - Daniel P Bray
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
| | - Garvin B Perry
- Biosciences, Agriculture and Food Technologies, University of Trinidad and Tobago, Caroni North Bank Road, Arima, Trinidad and Tobago
| | - Leroy Grey
- Cocoa Industry Board of Jamaica, Marcus Garvey Drive, Kingston, Jamaica
| | - Steven R Belmain
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
| | - Philip C Stevenson
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
- Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
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Mkenda PA, Ndakidemi PA, Stevenson PC, Arnold SEJ, Belmain SR, Chidege M, Gurr GM, Woolley VC. Characterization of Hymenopteran Parasitoids of Aphis fabae in an African Smallholder Bean Farming System through Sequencing of COI 'Mini-Barcodes'. Insects 2019; 10:insects10100331. [PMID: 31581700 PMCID: PMC6835700 DOI: 10.3390/insects10100331] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/08/2019] [Accepted: 09/29/2019] [Indexed: 11/30/2022]
Abstract
Parasitoids are among the most frequently reported natural enemies of insect pests, particularly aphids. The efficacy of parasitoids as biocontrol agents is influenced by biotic and abiotic factors. For example, hyperparasitoids can reduce the abundance of the primary parasitoids as well as modify their behavior. A field study was conducted at three contrasting elevations on Mount Kilimanjaro, Tanzania, to identify the parasitoids of aphids in smallholder bean farming agroecosystems. Sentinel aphids (Aphis fabae) on potted bean plants (Phaseolus vulgaris) were exposed in 15 bean fields at three elevations for 2 days. The sentinel aphids were then kept in cages in a greenhouse until emergence of the parasitoids, which were collected and preserved in 98% ethanol for identification. Of the 214 parasitoids that emerged from sentinel aphids, the greatest abundance (44.86%) were from those placed at intermediate elevations (1000–1500 m a.s.l), compared to 42.52% from the lowest elevations and only 12.62% from the highest elevation farms. Morphological identification of the parasitoids that emerged from parasitized aphids showed that 90% were Aphidius species (Hymenoptera: Braconidae: Aphidiinae). Further characterization by sequencing DNA ‘mini-barcodes’ identified parasitoids with ≥99% sequence similarity to Aphidius colemani, 94–95% sequence similarity to Pachyneuron aphidis and 90% similarity to a Charipinae sp. in the National Center for Biotechnology Information (NCBI) database. These results confidently identified A. colemani as the dominant primary aphid parasitoid of A. fabae in the study area. A Pachyneuron sp., which was most closely related to P. aphidis, and a Charipinae sp. occurred as hyperparasitoids. Thus, interventions to improve landscapes and farming practice should monitor specifically how to augment populations of A. colemani, to ensure any changes enhance the delivery of natural pest regulation. Further studies are needed for continuous monitoring of the hyperparasitism levels and the dynamics of aphids, primary parasitoids, and secondary parasitoids in different cropping seasons and their implications in aphid control.
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Affiliation(s)
- Prisila A. Mkenda
- Department of Sustainable Agriculture, Biodiversity and Ecosystems Management, The Nelson Mandela African Institution of Science and Technology, Arusha PO Box 447, Tanzania; (P.A.M.); (P.A.N.)
- Graham Centre for Agricultural Innovation, Charles Sturt University, PO Box 883, Orange, NSW 2800, Australia;
| | - Patrick A. Ndakidemi
- Department of Sustainable Agriculture, Biodiversity and Ecosystems Management, The Nelson Mandela African Institution of Science and Technology, Arusha PO Box 447, Tanzania; (P.A.M.); (P.A.N.)
| | - Philip C. Stevenson
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; (P.C.S.); (S.E.J.A.); (S.R.B.)
- Royal Botanic Gardens, Kew, Richmond Surrey, TW9 3AB, UK
| | - Sarah E. J. Arnold
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; (P.C.S.); (S.E.J.A.); (S.R.B.)
| | - Steven R. Belmain
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; (P.C.S.); (S.E.J.A.); (S.R.B.)
| | - Maneno Chidege
- Department of Research, Plant Protection Division, Tropical Pesticide Research Institute (TPRI), Arusha PO Box 3024, Tanzania;
| | - Geoff M. Gurr
- Graham Centre for Agricultural Innovation, Charles Sturt University, PO Box 883, Orange, NSW 2800, Australia;
- Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 35002, China
| | - Victoria C. Woolley
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK; (P.C.S.); (S.E.J.A.); (S.R.B.)
- Correspondence:
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Koch H, Woodward J, Langat MK, Brown MJ, Stevenson PC. Flagellum Removal by a Nectar Metabolite Inhibits Infectivity of a Bumblebee Parasite. Curr Biol 2019; 29:3494-3500.e5. [DOI: 10.1016/j.cub.2019.08.037] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/13/2019] [Accepted: 08/15/2019] [Indexed: 12/21/2022]
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Davis JK, Aguirre LA, Barber NA, Stevenson PC, Adler LS. From plant fungi to bee parasites: mycorrhizae and soil nutrients shape floral chemistry and bee pathogens. Ecology 2019; 100:e02801. [PMID: 31234229 PMCID: PMC6773465 DOI: 10.1002/ecy.2801] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 04/16/2019] [Accepted: 05/28/2019] [Indexed: 12/19/2022]
Abstract
Bee populations have experienced declines in recent years, due in part to increased disease incidence. Multiple factors influence bee-pathogen interactions, including nectar and pollen quality and secondary metabolites. However, we lack an understanding of how plant interactions with their environment shape bee diet quality. We examined how plant interactions with the belowground environment alter floral rewards and, in turn, bee-pathogen interactions. Soil-dwelling mycorrhizal fungi are considered plant mutualists, although the outcome of the relationship depends on environmental conditions such as nutrients. In a 2 × 2 factorial design, we asked whether mycorrhizal fungi and nutrients affect concentrations of nectar and pollen alkaloids (anabasine and nicotine) previously shown to reduce infection by the gut pathogen Crithidia in the native bumble bee Bombus impatiens. To ask how plant interactions affect this common bee pathogen, we fed pollen and nectar from our treatment plants, and from a wildflower pollen control with artificial nectar, to bees infected with Crithidia. Mycorrhizal fungi and fertilizer both influenced flowering phenology and floral chemistry. While we found no anabasine or nicotine in nectar, high fertilizer increased anabasine and nicotine in pollen. Arbuscular mycorrhizal fungi (AMF) decreased nicotine concentrations, but the reduction due to AMF was stronger in high than low-nutrient conditions. AMF and nutrients also had interactive effects on bee pathogens via changes in nectar and pollen. High fertilizer reduced Crithidia cell counts relative to low fertilizer in AMF plants, but increased Crithidia in non-AMF plants. These results did not correspond with effects of fertilizer and AMF on pollen alkaloid concentrations, suggesting that other components of pollen or nectar were affected by treatments and shaped pathogen counts. Our results indicate that soil biotic and abiotic environment can alter bee-pathogen interactions via changes in floral rewards, and underscore the importance of integrative studies to predict disease dynamics and ecological outcomes.
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Affiliation(s)
- Julie K. Davis
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA
- Department of Entomology, Cornell University, Ithaca, NY 14850, USA
| | - Luis A. Aguirre
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Nicholas A. Barber
- Department of Biological Sciences, San Diego State University, San Diego, CA 92182, USA
| | - Philip C. Stevenson
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Surrey TW9 3AB, UK
- Natural Resources Institute, University of Greenwich, Chatham, Kent ME4 4TB, UK
| | - Lynn S. Adler
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
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Scott-Brown AS, Arnold SEJ, Kite GC, Farrell IW, Farman DI, Collins DW, Stevenson PC. Mechanisms in mutualisms: a chemically mediated thrips pollination strategy in common elder. Planta 2019; 250:367-379. [PMID: 31069523 DOI: 10.1007/s00425-019-03176-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 04/26/2019] [Indexed: 06/09/2023]
Abstract
This study provides first evidence of a thrips species pollinating Sambucus nigra and describes how interactions are driven by plant biochemical signalling and moderated by temporal changes in floral chemistry. The concept of flower-feeding thrips as pollinating insects in temperate regions is rarely considered as they are more frequently regarded to be destructive florivores feeding on pollen and surrounding plant tissue. Combining laboratory and field-based studies we examined interactions between Sambucus nigra (elderflower) and Thrips major within their native range to ascertain the role of thrips in the pollination of this species and to determine if floral chemicals mediated flower visits. If thrips provide a pollination service to S. nigra, then this will likely manifest in traits that attract the pollinating taxa at temporally critical points in floral development. T. major were highly abundant in inflorescences of S. nigra, entering flowers when stigmas were pollen-receptive and anthers were immature. When thrips were excluded from the inflorescences, fruit-set failed. Linalool was the major component of the inflorescence headspace with peak abundance coinciding with the highest number of adult thrips visiting flowers. Thrips were absent in buds and their numbers declined again in senescing flowers inversely correlating with the concentration of cyanogenic glycosides recorded in the floral tissue. Our data show that S. nigra floral chemistry mediates the behaviour of pollen-feeding thrips by attracting adults in high numbers to the flowers at pre-anthesis stage, while producing deterrent compounds prior to fruit development. Taking an integrative approach to studying thrips behaviour and floral biology we provide a new insight into the previously ambiguously defined pollination strategies of S. nigra and provide evidence suggesting that the relationship between T. major and S. nigra is mutualistic.
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Affiliation(s)
| | - Sarah E J Arnold
- Natural Resources Institute, University of Greenwich, Chatham Maritime, ME4 4TB, UK
| | | | | | - Dudley I Farman
- Natural Resources Institute, University of Greenwich, Chatham Maritime, ME4 4TB, UK
| | | | - Philip C Stevenson
- Royal Botanic Gardens Kew, Richmond, TW9 3AB, UK
- Natural Resources Institute, University of Greenwich, Chatham Maritime, ME4 4TB, UK
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Palmer‐Young EC, Farrell IW, Adler LS, Milano NJ, Egan PA, Irwin RE, Stevenson PC. Secondary metabolites from nectar and pollen: a resource for ecological and evolutionary studies. Ecology 2019; 100:e02621. [DOI: 10.1002/ecy.2621] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/05/2018] [Accepted: 12/20/2018] [Indexed: 11/07/2022]
Affiliation(s)
- Evan C. Palmer‐Young
- Department of Biology University of Massachusetts at Amherst Amherst Massachusetts 01003 USA
| | - Iain W. Farrell
- Royal Botanic Gardens Kew, Richmond Surrey TW9 3AE United Kingdom
| | - Lynn S. Adler
- Department of Biology University of Massachusetts at Amherst Amherst Massachusetts 01003 USA
| | - Nelson J. Milano
- Department of Biology University of Massachusetts at Amherst Amherst Massachusetts 01003 USA
| | - Paul A. Egan
- Department of Plant Protection Biology Swedish University of Agricultural Sciences SE‐23053 Alnarp Sweden
| | - Rebecca E. Irwin
- Department of Applied Ecology North Carolina State University Raleigh North Carolina 27695 USA
| | - Philip C. Stevenson
- Royal Botanic Gardens Kew, Richmond Surrey TW9 3AE United Kingdom
- University of Greenwich Medway ME4 4 TB United Kingdom
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Palmer-Young EC, Farrell IW, Adler LS, Milano NJ, Egan PA, Junker RR, Irwin RE, Stevenson PC. Chemistry of floral rewards: intra- and interspecific variability of nectar and pollen secondary metabolites across taxa. ECOL MONOGR 2018. [DOI: 10.1002/ecm.1335] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Evan C. Palmer-Young
- Department of Biology; University of Massachusetts at Amherst; Amherst Massachusetts 01003 USA
| | - Iain W. Farrell
- Royal Botanic Gardens, Kew; Richmond Surrey TW9 3AB United Kingdom
| | - Lynn S. Adler
- Department of Biology; University of Massachusetts at Amherst; Amherst Massachusetts 01003 USA
| | - Nelson J. Milano
- Department of Biology; University of Massachusetts at Amherst; Amherst Massachusetts 01003 USA
| | - Paul A. Egan
- Department of Plant Protection Biology; Swedish University of Agricultural Sciences; SE-23053 Alnarp Sweden
| | - Robert R. Junker
- Department of Bioscience; University of Salzburg; Hellbrunnerstrasse 34 5020 Salzburg Austria
| | - Rebecca E. Irwin
- Department of Applied Ecology; North Carolina State University; Raleigh North Carolina 27695 USA
| | - Philip C. Stevenson
- Royal Botanic Gardens, Kew; Richmond Surrey TW9 3AB United Kingdom
- University of Greenwich; Medway ME4 4 TB United Kingdom
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Stevenson PC, Green PWC, Farrell IW, Brankin A, Mvumi BM, Belmain SR. Novel Agmatine Derivatives in Maerua edulis With Bioactivity Against Callosobruchus maculatus, a Cosmopolitan Storage Insect Pest. Front Plant Sci 2018; 9:1506. [PMID: 30386361 PMCID: PMC6200017 DOI: 10.3389/fpls.2018.01506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/26/2018] [Indexed: 06/08/2023]
Abstract
Food security in developing countries is threatened by crop pests and ectoparasites in livestock. Strategies for their management still rely on synthetic pesticides which are not always effective and the active ingredients persist in the environment with negative consequences for beneficial arthropods, farmers and consumers, hence necessitating research on sustainable alternatives. Botanical insecticides are increasingly relevant, typically having lower impacts on users, consumers and the environment. One example is the southern African shrub the Blue bush-berry, Maerua edulis. Recent work reported effective pest control using this plant species against cattle ticks, storage beetles and vegetable pests. However, little is known about the chemistry underlying activity and this is essential to optimize its use. Here, we identified two novel plant chemical structures, the E and Z isomers of cinnamoyl-4-aminobutylguanidine along with the E and Z isomers of 4-hydroxycinnamoyl-4-aminobutylguanidine in the leaves of M. edulis. We isolated these compounds from the leaves and elucidated their chemical structures using various spectroscopic techniques including High Resolution Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy. We also identified a further 11 closely related structures of which 6 are tentatively reported here for the first time. Stachydrine and 3-hydroxystachydrine were also identified in the leaf extract, and occurred at very high concentrations; up to 2% w/w of dry leaves. We tested these two compounds, along with the 4 main cinnamoylamides and the crude M. edulis leaf extract against the cowpea bruchid Callosobruchus maculatus at concentrations equivalent to those present in extracts used by smallholder farmers. Mortality of insects exposed to crude plant extracts after 72 h was significantly higher than the untreated control although still lower than for insects exposed to rotenone, the positive control. The two new compounds and stachydrine showed similar activity to the crude extracts suggesting that these compounds explained the activity of the extract. After 6 days, the mortality of insects exposed to crude extracts and isolated compounds was similar to that recorded with the positive control. The stachydrine fraction and the E and Z isomers of cinnamoyl-4-aminobutylguanidine also inhibited oviposition activity in fecund female beetles. Our data show that methanol extracts of M. edulis were toxic to C. maculatus and inhibited oviposition even at 0.1% w/v so these foliar chemicals may explain the activity of the plant material. We also synthesized the amides which facilitated structural elucidation, produced adequate quantities for testing and demonstrated the potential for commercial synthesis.
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Affiliation(s)
- Philip C. Stevenson
- Natural Resources Institute, University of Greenwich, Chatham, United Kingdom
- Royal Botanic Gardens, London, United Kingdom
| | - Paul W. C. Green
- Royal Botanic Gardens, London, United Kingdom
- Jealott’s Hill International Research Centre, Syngenta, Bracknell, United Kingdom
| | | | | | - Brighton M. Mvumi
- Department of Soil Science and Agricultural Engineering, University of Zimbabwe, Harare, Zimbabwe
| | - Steven R. Belmain
- Natural Resources Institute, University of Greenwich, Chatham, United Kingdom
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Adler LS, Michaud KM, Ellner SP, McArt SH, Stevenson PC, Irwin RE. Disease where you dine: plant species and floral traits associated with pathogen transmission in bumble bees. Ecology 2018; 99:2535-2545. [PMID: 30155907 DOI: 10.1002/ecy.2503] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 06/15/2018] [Accepted: 07/05/2018] [Indexed: 11/11/2022]
Abstract
Hotspots of disease transmission can strongly influence pathogen spread. Bee pathogens may be transmitted via shared floral use, but the role of plant species and floral trait variation in shaping transmission dynamics is almost entirely unexplored. Given the importance of pathogens for the decline of several bee species, understanding whether and how plant species and floral traits affect transmission could give us important tools for predicting which plant species may be hotspots for disease spread. We assessed variation in transmission via susceptibility (probability of infection) and mean intensity (cell count of infected bees) of the trypanosomatid gut pathogen Crithidia bombi to uninfected Bombus impatiens workers foraging on 14 plant species, and assessed the role of floral traits, bee size and foraging behavior on transmission. We also conducted a manipulative experiment to determine how the number of open flowers affected transmission on three plant species, Penstemon digitalis, Monarda didyma, and Lythrum salicaria. Plant species differed fourfold in the overall mean abundance of Crithidia in foraging bumble bees (mean including infected and uninfected bees). Across plant species, bee susceptibility and mean intensity increased with the number of reproductive structures per inflorescence (buds, flowers and fruits); smaller bees and those that foraged longer were also more susceptible. Trait-based models were as good or better than species-based models at predicting susceptibility and mean intensity based on AIC values. Surprisingly, floral size and morphology did not significantly predict transmission across species. In the manipulative experiment, more open flowers increased mean pathogen abundance fourfold in Monarda, but had no effect in the other two plant species. Our results suggest that variation among plant species, through their influence on pathogen transmission, may shape bee disease dynamics. Given widespread investment in pollinator-friendly plantings to support pollinators, understanding how plant species affect disease transmission is important for recommending plant species that optimize pollinator health.
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Affiliation(s)
- Lynn S Adler
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, 01003, USA
| | - Kristen M Michaud
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, 01003, USA
| | - Stephen P Ellner
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, 14853, USA
| | - Scott H McArt
- Department of Entomology, Cornell University, Ithaca, New York, 14853, USA
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Richmond, TW9 3AB, UK.,Natural Resources Institute, University of Greenwich, Chatham, ME4 4TB, UK
| | - Rebecca E Irwin
- Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, 27695, USA
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42
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Egan PA, Adler LS, Irwin RE, Farrell IW, Palmer-Young EC, Stevenson PC. Crop Domestication Alters Floral Reward Chemistry With Potential Consequences for Pollinator Health. Front Plant Sci 2018; 9:1357. [PMID: 30319666 PMCID: PMC6169423 DOI: 10.3389/fpls.2018.01357] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/28/2018] [Indexed: 05/29/2023]
Abstract
Crop domestication can lead to weakened expression of plant defences, with repercussions for herbivore and pathogen susceptibility. However, little is known about how domestication alters traits that mediate other important ecological interactions in crops, such as pollination. Secondary metabolites, which underpin many defence responses in plants, also occur widely in nectar and pollen and influence plant-pollinator interactions. Thus, domestication may also affect secondary compounds in floral rewards, with potential consequences for pollinators. To test this hypothesis, we chemically analysed nectar and pollen from wild and cultivated plants of highbush blueberry (Vaccinium corymbosum L.), before conducting an artificial diet bioassay to examine pollinator-pathogen interactions. Our results indicated that domestication has significantly altered the chemical composition of V. corymbosum nectar and pollen, and reduced pollen chemical diversity in cultivated plants. Of 20 plant metabolites identified in floral rewards, 13 differed significantly between wild and cultivated plants, with a majority showing positive associations with wild compared to cultivated plants. These included the amino acid phenylalanine (4.5 times higher in wild nectar, 11 times higher in wild pollen), a known bee phagostimulant and essential nutrient; and the antimicrobial caffeic acid ester 4-O-caffeoylshikimic acid (two times higher in wild nectar). We assessed the possible biological relevance of variation in caffeic acid esters in bioassays, using the commercially available 3-O-caffeoylquinic acid. This compound reduced Bombus impatiens infection by a prominent gut pathogen (Crithidia) at concentrations that occurred in wild but not cultivated plants, suggesting that domestication may influence floral traits with consequences for bee health. Appreciable levels of genetic variation and heritability were found for most floral reward chemical traits, indicating good potential for selective breeding. Our study provides the first assessment of plant domestication effects on floral reward chemistry and its potential repercussions for pollinator health. Given the central importance of pollinators for agriculture, we discuss the need to extend such investigations to pollinator-dependent crops more generally and elaborate on future research directions to ascertain wider trends, consequences for pollinators, mechanisms, and breeding solutions.
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Affiliation(s)
- Paul A. Egan
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Lynn S. Adler
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, United States
| | - Rebecca E. Irwin
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, United States
| | | | - Evan C. Palmer-Young
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, United States
| | - Philip C. Stevenson
- Royal Botanic Gardens, Kew, Richmond, United Kingdom
- Natural Resources Institute, University of Greenwich, London, United Kingdom
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43
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Tembo Y, Mkindi AG, Mkenda PA, Mpumi N, Mwanauta R, Stevenson PC, Ndakidemi PA, Belmain SR. Pesticidal Plant Extracts Improve Yield and Reduce Insect Pests on Legume Crops Without Harming Beneficial Arthropods. Front Plant Sci 2018; 9:1425. [PMID: 30323823 PMCID: PMC6172852 DOI: 10.3389/fpls.2018.01425] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 09/07/2018] [Indexed: 05/22/2023]
Abstract
In the fight against arthropod crop pests using plant secondary metabolites, most research has focussed on the identification of bioactive molecules. Several hundred candidate plant species and compounds are now known to have pesticidal properties against a range of arthropod pest species. Despite this growing body of research, few natural products are commercialized for pest management whilst on-farm use of existing botanically-based pesticides remains a small, but growing, component of crop protection practice. Uptake of natural pesticides is at least partly constrained by limited data on the trade-offs of their use on farm. The research presented here assessed the potential trade-offs of using pesticidal plant extracts on legume crop yields and the regulating ecosystem services of natural pests enemies. The application of six established pesticidal plants (Bidens pilosa, Lantana camara, Lippia javanica, Tephrosia vogelii, Tithonia diversifolia, and Vernonia amygdalina) were compared to positive and negative controls for their impact on yields of bean (Phaseolus vulgaris), cowpea (Vigna unguiculata), and pigeon pea (Cajanus cajan) crops and the abundance of key indicator pest and predatory arthropod species. Analysis of field trials showed that pesticidal plant treatments often resulted in crop yields that were comparable to the use of a synthetic pesticide (lambda-cyhalothrin). The best-performing plant species were T. vogelii, T. diversifolia, and L. javanica. The abundance of pests was very low when using the synthetic pesticide, whilst the plant extracts generally had a higher number of pests than the synthetic but lower numbers than observed on the negative controls. Beneficial arthropod numbers were low with synthetic treated crops, whereas the pesticidal plant treatments appeared to have little effect on beneficials when compared to the negative controls. The outcomes of this research suggest that using extracts of pesticidal plants to control pests can be as effective as synthetic insecticides in terms of crop yields while tritrophic effects were reduced, conserving the non-target arthropods that provide important ecosystem services such as pollination and pest regulation. Thus managing crop pests using plant secondary metabolites can be more easily integrated in to agro-ecologically sustainable crop production systems.
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Affiliation(s)
- Yolice Tembo
- Lilongwe University of Agriculture and Natural Resources, Lilongwe, Malawi
| | - Angela G. Mkindi
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Prisila A. Mkenda
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Nelson Mpumi
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Regina Mwanauta
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Philip C. Stevenson
- Jodrell Laboratory, Royal Botanic Gardens, Richmond, United Kingdom
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, United Kingdom
| | | | - Steven R. Belmain
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, United Kingdom
- *Correspondence: Steven R. Belmain
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44
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Koch H, Stevenson PC. Do linden trees kill bees? Reviewing the causes of bee deaths on silver linden ( Tilia tomentosa). Biol Lett 2017; 13:rsbl.2017.0484. [PMID: 28954857 DOI: 10.1098/rsbl.2017.0484] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/01/2017] [Indexed: 11/12/2022] Open
Abstract
For decades, linden trees (basswoods or lime trees), and particularly silver linden (Tilia tomentosa), have been linked to mass bee deaths. This phenomenon is often attributed to the purported occurrence of the carbohydrate mannose, which is toxic to bees, in Tilia nectar. In this review, however, we conclude that from existing literature there is no experimental evidence for toxicity to bees in linden nectar. Bee deaths on Tilia probably result from starvation, owing to insufficient nectar resources late in the tree's flowering period. We recommend ensuring sufficient alternative food sources in cities during late summer to reduce bee deaths on silver linden. Silver linden metabolites such as floral volatiles, pollen chemistry and nectar secondary compounds remain underexplored, particularly their toxic or behavioural effects on bees. Some evidence for the presence of caffeine in linden nectar may mean that linden trees can chemically deceive foraging bees to make sub-optimal foraging decisions, in some cases leading to their starvation.
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Affiliation(s)
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Surrey, UK.,Natural Resources Institute, University of Greenwich, Kent, UK
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45
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Barlow SE, Wright GA, Ma C, Barberis M, Farrell IW, Marr EC, Brankin A, Pavlik BM, Stevenson PC. Distasteful Nectar Deters Floral Robbery. Curr Biol 2017; 27:2552-2558.e3. [DOI: 10.1016/j.cub.2017.07.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/23/2017] [Accepted: 07/04/2017] [Indexed: 10/19/2022]
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46
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Anyanga MO, Yada B, Yencho GC, Ssemakula GN, Alajo A, Farman DI, Mwanga ROM, Stevenson PC. Segregation of Hydroxycinnamic Acid Esters Mediating Sweetpotato Weevil Resistance in Storage Roots of Sweetpotato. Front Plant Sci 2017; 8:1011. [PMID: 28659954 PMCID: PMC5468429 DOI: 10.3389/fpls.2017.01011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/26/2017] [Indexed: 06/07/2023]
Abstract
Resistance to sweetpotato weevils (Cylas spp.) has been identified in several sweetpotato (Ipomoea batatas) landraces from East Africa and shown to be conferred by hydroxycinnamic acids that occur on the surface of storage roots. The segregation of resistance in this crop is unknown and could be monitored using these chemical traits as markers for resistance in F1 offspring from breeding programs. For the first time in a segregating population, we quantified the plant chemicals that confer resistance and evaluated levels of insect colonization of the same progeny in field and laboratory studies. We used a bi-parental mapping population of 287 progenies from a cross between I. batatas 'New Kawogo,' a weevil resistant Ugandan landrace and I. batatas 'Beauregard' a North American orange-fleshed and weevil susceptible cultivar. The progenies were evaluated for resistance to sweetpotato weevil, Cylas puncticollis at three field locations that varied climatically and across two seasons to determine how environment and location influenced resistance. To augment our field open-choice resistance screening, each clone was also evaluated in a no choice experiment with weevils reared in the laboratory. Chemical analysis was used to determine whether differences in resistance to weevils were associated with plant compounds previously identified as conferring resistance. We established linkage between field and laboratory resistance to Cylas spp. and sweetpotato root chemistry. The data also showed that resistance in sweetpotato was mediated by root chemicals in most but not all cases. Multi-location trials especially from Serere data provided evidence that the hydroxycinnamic acid esters are produced constitutively within the plants in different clonal genotypes and that the ecological interaction of these chemicals in sweetpotato with weevils confers resistance. Our data suggest that these chemical traits are controlled quantitatively and that ultimately a knowledge of the genetics of resistance will facilitate management of these traits, enhance our understanding of the mechanistic basis of resistance and speed the development of new sweetpotato varieties with resistance to sweetpotato weevil.
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Affiliation(s)
- Milton O. Anyanga
- National Crops Resources Research Institute, National Agricultural Research OrganizationKampala, Uganda
- Department of Agriculture Health and Environment, Natural Resources Institute, University of GreenwichChatham, United Kingdom
| | - Benard Yada
- National Crops Resources Research Institute, National Agricultural Research OrganizationKampala, Uganda
- Department of Horticultural Science, North Carolina State University, RaleighNC, United States
| | - G. C. Yencho
- Department of Horticultural Science, North Carolina State University, RaleighNC, United States
| | - Gorrettie N. Ssemakula
- National Crops Resources Research Institute, National Agricultural Research OrganizationKampala, Uganda
| | - Agnes Alajo
- National Crops Resources Research Institute, National Agricultural Research OrganizationKampala, Uganda
| | - Dudley I. Farman
- Department of Agriculture Health and Environment, Natural Resources Institute, University of GreenwichChatham, United Kingdom
| | | | - Philip C. Stevenson
- Department of Agriculture Health and Environment, Natural Resources Institute, University of GreenwichChatham, United Kingdom
- Natural Capital and Plant Health, Royal Botanic Gardens, KewRichmond, United Kingdom
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47
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Folly AJ, Koch H, Stevenson PC, Brown MJF. Larvae act as a transient transmission hub for the prevalent bumblebee parasite Crithidia bombi. J Invertebr Pathol 2017; 148:81-85. [PMID: 28601566 PMCID: PMC5555351 DOI: 10.1016/j.jip.2017.06.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 05/12/2017] [Accepted: 06/06/2017] [Indexed: 10/26/2022]
Abstract
Disease transmission networks are key for understanding parasite epidemiology. Within the social insects, structured contact networks have been suggested to limit the spread of diseases to vulnerable members of their society, such as the queen or brood. However, even these complex social structures do not provide complete protection, as some diseases, which are transmitted by workers during brood care, can still infect the brood. Given the high rate of feeding interactions that occur in a social insect colony, larvae may act as disease transmission hubs. Here we use the bumblebee Bombus terrestris and its parasite Crithidia bombi to determine the role of brood in bumblebee disease transmission networks. Larvae that were artificially inoculated with C. bombi showed no signs of infection seven days after inoculation. However, larvae that received either an artificial inoculation or a contaminated feed from brood-caring workers were able to transmit the parasite to naive workers. These results suggest that the developing brood is a potential route of intracolonial disease transmission and should be included when considering social insect disease transmission networks.
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Affiliation(s)
| | | | - Philip C Stevenson
- Royal Botanic Gardens, Kew, UK; Natural Resources Institute, University of Greenwich, Kent, UK.
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48
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Koch H, Brown MJ, Stevenson PC. The role of disease in bee foraging ecology. Curr Opin Insect Sci 2017; 21:60-67. [PMID: 28822490 DOI: 10.1016/j.cois.2017.05.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/03/2017] [Accepted: 05/10/2017] [Indexed: 06/07/2023]
Abstract
Diseases have important but understudied effects on bee foraging ecology. Bees transmit and contract diseases on flowers, but floral traits including plant volatiles and inflorescence architecture may affect transmission. Diseases spill over from managed or invasive pollinators to native wild bee species, and impacts of emerging diseases are of particular concern, threatening pollinator populations and pollination services. Here we review how parasites can alter the foraging behaviour of bees by changing floral preferences and impairing foraging efficiency. We also consider how changes to pollinator behaviours alter or reduce pollination services. The availability of diverse floral resources can, however, ameliorate bee diseases and their impacts through better nutrition and antimicrobial effects of plant compounds in pollen and nectar.
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Affiliation(s)
| | - Mark Jf Brown
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, UK
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Surrey, UK; Natural Resources Institute, University of Greenwich, Kent, UK
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49
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Guerra PC, Keil CB, Stevenson PC, Mina D, Samaniego S, Peralta E, Mazon N, Chancellor TCB. Larval Performance and Adult Attraction of Delia platura (Diptera: Anthomyiidae) in a Native and an Introduced Crop. J Econ Entomol 2017; 110:186-191. [PMID: 28011683 DOI: 10.1093/jee/tow237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Delia platura Meigen is an important pest in crops around the world. Its host range includes almost 50 species, and it can develop in soil organic matter. In Ecuador, D. platura is a serious problem for the crop, Lupinus mutabilis Sweet (Chocho), and it also attacks broccoli (Brassica oleracea L.). After broccoli is harvested, crop residue is mixed with soil or collected and stored close to Chocho fields. The objectives of this study were to determine the adaptive responses of larvae reared on different hosts and whether D. platura females are preferentially attracted to germinating L. mutabilis seeds or broccoli residue. Accordingly, larval performance and attraction of female D. platura reared on broccoli residue and L. mutabilis seeds were evaluated. The number of larvae, pupae, and adults were higher when reared on broccoli. Conversely, pupal weight was higher and time from larva to pupa, pupa to adult, and total life cycle were longer in flies reared on L. mutabilis. Although D. platura developed more quickly on broccoli, L. mutabilis was also a good host since pupae were heavier compared with flies reared on broccoli. Delia platura females reared on broccoli preferred broccoli residue to L. mutabilis in an olfactometer. Volatiles from broccoli residue in soil may attract D. platura females and stimulate oviposition on L. mutabilis seeds. Environmentally benign production of L. mutabilis crops with minimal insecticide applications may require the elimination of fresh broccoli residue as fertilizer in soils where L. mutabilis is cultivated.
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Affiliation(s)
- Patricia C Guerra
- Natural Resources Institute, University of Greenwich, Greenwich, United Kingdom
| | - Clifford B Keil
- Pontifical Catholic University of Ecuador, School of Biological Sciences, Museum of Invertebrates, Quito, Ecuador
| | - Philip C Stevenson
- Natural Resources Institute, University of Greenwich, Greenwich, United Kingdom
- Royal Botanic Gardens, Kew, Surrey, United Kingdom
| | - Diego Mina
- Instituto Nacional de Investigaciones Agropecuarias, Programa Nacional de Leguminosas y Granos Andinos, Quito, Ecuador
| | - Servio Samaniego
- Instituto Nacional de Investigaciones Agropecuarias, Programa Nacional de Leguminosas y Granos Andinos, Quito, Ecuador
| | - Eduardo Peralta
- Instituto Nacional de Investigaciones Agropecuarias, Programa Nacional de Leguminosas y Granos Andinos, Quito, Ecuador
| | - Nelson Mazon
- Instituto Nacional de Investigaciones Agropecuarias, Programa Nacional de Leguminosas y Granos Andinos, Quito, Ecuador
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50
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Scott-Brown AS, Gregory T, Farrell IW, Stevenson PC. Leaf trichomes and foliar chemistry mediate defence against glasshouse thrips; Heliothrips haemorrhoidalis (Bouché) in Rhododendron simsii. Funct Plant Biol 2016; 43:1170-1182. [PMID: 32480536 DOI: 10.1071/fp16045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 08/10/2016] [Indexed: 06/11/2023]
Abstract
Herbivore defence mechanisms are a costly diversion of resources away from growth and reproduction. Thus time-limited and tissue specific expression in critical plant parts is more efficient as defined by optimal defence theory. Surprisingly little is known about Rhododendron herbivore defence but it may be mediated by combined chemical and physical mechanisms. Rhododendron simsii Planch. survives cyclic infestations of a leaf-feeding thrips, Heliothrips haemorrhoidalis (Bouché), which severely damage mature leaves but avoid terminal young leaves suggesting specific, localised defence expression. We examined correlations between the distribution of thrips and feeding damage with density of trichomes and the concentration of the diterpenoid, grayanotoxin I, a compound implicated in but not previously reported to mediate invertebrate defence in Rhododendron. Our data show that as leaves matured the number of thrips and area of feeding damage increased as trichome density and grayanotoxin I concentration decreased, this inverse correlation suggesting trichomes and grayanotoxin I mediate defence in younger leaf tissue. Grayanotoxin I was tested against H. haemorrhoidalis and was toxic to immature life stages and repellent to the adult thrips, reducing numbers of first instars emerging on leaves when applied at ecologically relevant concentrations. This work demonstrates that the pattern of defensive traits in foliage of a species of Rhododendron is key to its ability to tolerate cyclic infestations of a generalist herbivore, effectively conserving vital tissues required for growth and reproduction.
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Affiliation(s)
- Alison S Scott-Brown
- Department of Natural Capital and Plant Health, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
| | - Tom Gregory
- UCL Institute of Archaeology, 31-34 Gordon Square, London, WC1H 0PY, UK
| | - Iain W Farrell
- Department of Natural Capital and Plant Health, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
| | - Philip C Stevenson
- Department of Natural Capital and Plant Health, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
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