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Cuff JP, Evans DM, Vaughan IP, Wilder SM, Tercel MPTG, Windsor FM. Networking nutrients: How nutrition determines the structure of ecological networks. J Anim Ecol 2024; 93:974-988. [PMID: 38946110 DOI: 10.1111/1365-2656.14124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 05/29/2024] [Indexed: 07/02/2024]
Abstract
Nutrients can shape ecological interactions but remain poorly integrated into ecological networks. Concepts such as nutrient-specific foraging nevertheless have the potential to expose the mechanisms structuring complex ecological systems. Nutrients also present an opportunity to predict dynamic processes, such as interaction rewiring and extinction cascades, and increase the accuracy of network analyses. Here, we propose the concept of nutritional networks. By integrating nutritional data into ecological networks, we envisage significant advances to our understanding of ecological processes from individual to ecosystem scales. We show that networks can be constructed with nutritional data to illuminate how nutrients structure ecological interactions in natural systems through an empirical example. Throughout, we identify fundamental ecological hypotheses that can be explored in a nutritional network context, alongside methods for resolving those networks. Nutrients influence the structure and complexity of ecological networks through mechanistic processes and concepts including nutritional niche differentiation, functional responses, landscape diversity, ecological invasions and ecosystem robustness. Future research on ecological networks should consider nutrients when investigating the drivers of network structure and function.
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Affiliation(s)
- Jordan P Cuff
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Darren M Evans
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Ian P Vaughan
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Shawn M Wilder
- Department of Integrative Biology, 501 Life Sciences West, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Maximillian P T G Tercel
- School of Biosciences, Cardiff University, Cardiff, UK
- Durrell Wildlife Conservation Trust, Trinity, Jersey
| | - Fredric M Windsor
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
- School of Biosciences, Cardiff University, Cardiff, UK
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2
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Olaboro S, Kyamanywa S, Lutaakome M, Paparu P, Halerimana C, Nkalubo ST, Otim MH. Feeding Preferences of the Bean Leaf Beetle (Ootheca spp.) (Coleoptera: Chrysomelidae): Insights for Targeted Pest Control Strategies in Uganda. INSECTS 2024; 15:516. [PMID: 39057249 PMCID: PMC11277491 DOI: 10.3390/insects15070516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 06/18/2024] [Accepted: 06/25/2024] [Indexed: 07/28/2024]
Abstract
The bean leaf beetle (BLB) (Ootheca spp.) is a polyphagous pest causing significant yield losses in Uganda, particularly in the Northern and Eastern regions on various hosts plants. Despite its polyphagous behaviour, the BLB exhibits preferential feeding, offering an opportunity for targeted pest management. This study explored its feeding preferences across seven crops: common bean, cowpea, greengram, okra, roselle (malakwang), groundnuts, and soybean. This study was conducted in Arua and Lira districts using a randomized complete block design for two rainy seasons (2018A and 2018B). The results showed significant differences in BLB abundance and foliar damage among host crops, locations, days after planting and seasons. Cowpea was the most preferred crop while groundnuts was the least preferred. Therefore, cowpea can be recommended for use as a trap for managing Ootheca spp. in gardens where it is not the main crop. There was a higher pest abundance in Arua than in Lira. There was also a higher pest abundance in 2018A than in 2018B. These findings highlight the importance of understanding BLB's feeding preferences for implementing effective IPM strategies, emphasizing the potential role of trap cropping, especially with cowpea, to minimize BLB damage in resource-constrained agricultural settings.
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Affiliation(s)
- Samuel Olaboro
- National Crops Resources Research Institute, Namulonge, Kampala P.O. Box 7084, Uganda; (M.L.); (P.P.); (S.T.N.)
- Department of Agricultural Production, College of Agricultural and Environmental Sciences, Makerere University, Kampala P.O. Box 7062, Uganda; (S.K.); (C.H.)
| | - Samuel Kyamanywa
- Department of Agricultural Production, College of Agricultural and Environmental Sciences, Makerere University, Kampala P.O. Box 7062, Uganda; (S.K.); (C.H.)
| | - Moses Lutaakome
- National Crops Resources Research Institute, Namulonge, Kampala P.O. Box 7084, Uganda; (M.L.); (P.P.); (S.T.N.)
- Department of Agricultural Production, College of Agricultural and Environmental Sciences, Makerere University, Kampala P.O. Box 7062, Uganda; (S.K.); (C.H.)
| | - Pamela Paparu
- National Crops Resources Research Institute, Namulonge, Kampala P.O. Box 7084, Uganda; (M.L.); (P.P.); (S.T.N.)
| | - Charles Halerimana
- Department of Agricultural Production, College of Agricultural and Environmental Sciences, Makerere University, Kampala P.O. Box 7062, Uganda; (S.K.); (C.H.)
- National Coffee Research Institute, Kituuza, Mukono P.O. Box 185, Uganda
| | - Stanley Tamusange Nkalubo
- National Crops Resources Research Institute, Namulonge, Kampala P.O. Box 7084, Uganda; (M.L.); (P.P.); (S.T.N.)
| | - Michael Hilary. Otim
- National Crops Resources Research Institute, Namulonge, Kampala P.O. Box 7084, Uganda; (M.L.); (P.P.); (S.T.N.)
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3
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Laurie S, Ainslie L, Mitchell S, Morimoto J. Turmeric shortens lifespan in houseflies. FRONTIERS IN INSECT SCIENCE 2024; 4:1376011. [PMID: 38660018 PMCID: PMC11040687 DOI: 10.3389/finsc.2024.1376011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 03/11/2024] [Indexed: 04/26/2024]
Abstract
Climate change poses a significant threat to food security and global public health with the increasing likelihood of insect pest outbreaks. Alternative ways to control insect populations, preferably using environmental-friendly compounds, are needed. Turmeric has been suggested as a natural insecticide with toxicity properties in some insect groups. However, empirical evidence of the effects of turmeric - and their interaction with other ecological factors such as diet - on insect survival has been limited. Here, we tested the effects of turmeric and its interactions with diets differing in protein source in the common housefly, Musca domestica. We found that turmeric shortened lifespan independent of diet and sex. Females in turmeric diets were heavier at death, which was likely driven by a combination of relatively lower rates of body mass loss during their lifetime and a higher percentage of water content at death. Each sex responded differently to the protein source in the diet, and the magnitude of the difference in lifespan between sexes were greatest in diets in which protein source was hydrolysed yeast; individuals from both sexes lived longest in sucrose-milk diets and shortest in diets with hydrolysed yeast. There was no evidence of an interaction between turmeric and diet, suggesting that the toxicity effects are independent of protein source in the diet. Given the seemingly opposing effects of turmeric in insects and mammals being uncovered in the literature, our findings provide further evidence in support of turmeric as a potential natural insecticide.
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Affiliation(s)
- Sophie Laurie
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Leah Ainslie
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Sharon Mitchell
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Juliano Morimoto
- Institute of Mathematics, University of Aberdeen, King’s College, Aberdeen, United Kingdom
- Programa de Pós-graduação em Ecologia e Conservação, Universidade Federal do Paraná, Curitiba, Brazil
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4
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Anttonen P, Li Y, Chesters D, Davrinche A, Haider S, Bruelheide H, Chen JT, Wang MQ, Ma KP, Zhu CD, Schuldt A. Leaf Nutritional Content, Tree Richness, and Season Shape the Caterpillar Functional Trait Composition Hosted by Trees. INSECTS 2022; 13:1100. [PMID: 36555010 PMCID: PMC9785672 DOI: 10.3390/insects13121100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 11/25/2022] [Accepted: 11/26/2022] [Indexed: 06/17/2023]
Abstract
Nutritional content of host plants is expected to drive caterpillar species assemblages and their trait composition. These relationships are altered by tree richness-induced neighborhood variation and a seasonal decline in leaf quality. We tested how key functional traits related to the growth and defenses of the average caterpillar hosted by a tree species are shaped by nutritional host quality. We measured morphological traits and estimated plant community-level diet breadth based on occurrences from 1020 caterpillars representing 146 species in a subtropical tree diversity experiment from spring to autumn in one year. We focused on interspecific caterpillar trait variation by analyzing presence-only patterns of caterpillar species for each tree species. Our results show that tree richness positively affected caterpillar species-sharing among tree species, which resulted in lowered trait variation and led to higher caterpillar richness for each tree species. However, community-level diet breadth depended more on the nutritional content of host trees. Higher nutritional quality also supported species-poorer but more abundant communities of smaller and less well-defended caterpillars. This study demonstrates that the leaf nutritional quality of trees shapes caterpillar trait composition across diverse species assemblages at fine spatial scales in a way that can be predicted by ecological theory.
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Affiliation(s)
- Perttu Anttonen
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, 06108 Halle, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103 Leipzig, Germany
| | - Yi Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Douglas Chesters
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- International College, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Andréa Davrinche
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, 06108 Halle, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103 Leipzig, Germany
| | - Sylvia Haider
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, 06108 Halle, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103 Leipzig, Germany
| | - Helge Bruelheide
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, 06108 Halle, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103 Leipzig, Germany
| | - Jing-Ting Chen
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- College of Biological Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ming-Qiang Wang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ke-Ping Ma
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Chao-Dong Zhu
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- International College, University of Chinese Academy of Sciences, Beijing 100049, China
- College of Biological Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- State Key Laboratory of Integrated Pest Management, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Andreas Schuldt
- Department of Forest Nature Conservation, Georg-August-University Göttingen, 37077 Göttingen, Germany
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5
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Dinh H, Lundbäck I, Kumar S, Than AT, Morimoto J, Ponton F. Sugar-rich larval diet promotes lower adult pathogen load and higher survival after infection in a polyphagous fly. J Exp Biol 2022; 225:276376. [PMID: 35904096 DOI: 10.1242/jeb.243910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 07/19/2022] [Indexed: 11/20/2022]
Abstract
Nutrition is a central factor influencing immunity and resistance to infection, but the extent to which nutrition during development affects adult responses to infections is poorly understood. Our study investigated how the nutritional composition of the larval diet affects the survival, pathogen load, and food intake of adult fruit flies, Bactrocera tryoni, after septic bacterial infection. We found a sex-specific effect of larval diet composition on survival post-infection: survival rate was higher and bacterial load was lower for infected females fed sugar-rich larval diet compared with females fed protein-rich larval diet, an effect that was absent in males. Both males and females were heavier when fed a balanced larval diet compared to protein- or sugar-rich diet, while body lipid reserves were higher in the sugar-rich larval diet compared with other diets. Body protein reserve was lower for sugar-rich larval diets compared to other diets in males, but not females. Both females and males shifted their nutrient intake to ingest a sugar-rich diet when infected compared with sham-infected flies without any effect of the larval diet, suggesting that sugar-rich diets can be beneficial to fight off bacterial infection as shown in previous literature. Overall, our findings show that nutrition during early life can shape individual fitness in adulthood.
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Affiliation(s)
- Hue Dinh
- School of Natural Sciences, Macquarie University, Australia
| | - Ida Lundbäck
- School of Natural Sciences, Macquarie University, Australia
| | - Sheemal Kumar
- School of Natural Sciences, Macquarie University, Australia
| | - Anh The Than
- School of Natural Sciences, Macquarie University, Australia.,Department of Entomology, Vietnam National University of Agriculture, Vietnam
| | - Juliano Morimoto
- School of Natural Sciences, Macquarie University, Australia.,School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Ave, Aberdeen AB24 2TZ, UK.,Programa de Pós-graduação em Ecologia e Conservação, Universidade Federal do Paraná, Curitiba, 82590-300, Brazil
| | - Fleur Ponton
- School of Natural Sciences, Macquarie University, Australia
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Deans CA, Sword GA, Vogel H, Behmer ST. Quantity versus quality: Effects of diet protein-carbohydrate ratios and amounts on insect herbivore gene expression. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 145:103773. [PMID: 35405259 DOI: 10.1016/j.ibmb.2022.103773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/08/2022] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
Dietary protein and digestible carbohydrates are two key macronutrients for insect herbivores, but the amounts and ratios of these two macronutrients in plant vegetative tissues can be highly variable. Typically, insect herbivores regulate their protein-carbohydrate intake by feeding selectively on nutritionally complementary plant tissues, but this may not always be possible. Interestingly, lab experiments consistently demonstrate that performance - especially growth and survival - does not vary greatly when caterpillars and nymphal grasshoppers are reared on diets that differ in their protein-carbohydrate content. This suggests insect herbivores employ post-ingestive physiological mechanisms to compensate for variation in diet protein-carbohydrate profile. However, the molecular mechanisms that underlie this compensation are not well understood. Here we explore, for the first time in an insect herbivore, the transcriptional effects of two dietary factors: protein-to-carbohydrate ratio (p:c) and total macronutrient (p + c) content. Specifically, we reared Helicoverpa zea caterpillars on three diets that varied in diet p:c ratio and one diet that varied in total p + c concentration, all within an ecologically-relevant range. We observed two key findings. Caterpillars reared on diets with elevated total p + c content showed large differences in gene expression. In contrast, only small differences in gene expression were observed when caterpillars were reared on diets with different p:c ratios (spanning from protein-biased to carbohydrate-biased). The invariable expression of many metabolic genes across these variable diets suggests that H. zea caterpillars employ a strategy of constitutive expression to deal with protein-carbohydrate imbalances rather than diet-specific changes. This is further supported by two findings. First, few genes were uniquely associated with feeding on a protein- and carbohydrate-biased diet. Second, many differentially-expressed genes were shared across protein-biased, carbohydrate-biased, and concentrated diet treatments. Our study provides insights into the post-ingestive physiological mechanisms insect herbivores employ to regulate protein-carbohydrate intake. Most notably, it suggests that H. zea, and perhaps other generalist species, use similar post-ingestive mechanisms to deal with protein-carbohydrate imbalances - regardless of the direction of the imbalance.
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Affiliation(s)
- Carrie A Deans
- Department of Entomology, Texas A&M University, TAMU 2475, College Station, TX, 77843, USA; Department of Entomology, University of Minnesota, 219 Hodson Hall, St. Paul, MN, 55108, USA.
| | - Gregory A Sword
- Department of Entomology, Texas A&M University, TAMU 2475, College Station, TX, 77843, USA
| | - Heiko Vogel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, Jena, GER, 07745, USA
| | - Spencer T Behmer
- Department of Entomology, Texas A&M University, TAMU 2475, College Station, TX, 77843, USA
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7
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Austin AJ, Gilbert JDJ. Solitary bee larvae prioritize carbohydrate over protein in parentally provided pollen. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13746] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Alexander J. Austin
- Department of Biological and Marine Sciences University of Hull Hull UK
- Strategy & Environment Ku‐ring‐gai Council Gordon NSW Australia
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8
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Poissonnier LA, Simpson SJ, Dussutour A, Buhl C. Regulation of macronutrient intake in termites: A dietary self-selection experiment. JOURNAL OF INSECT PHYSIOLOGY 2020; 120:103983. [PMID: 31747550 DOI: 10.1016/j.jinsphys.2019.103983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 11/06/2019] [Accepted: 11/15/2019] [Indexed: 05/23/2023]
Abstract
Many animals have been shown to select among nutritionally complementary foods to reach a specific balance of nutrients that optimizes key life history traits. Nutritional ecology theory, however, predicts that an animal with a diet that is very stable in its composition, and with nutritional requirements that do not vary in their balance through time, would not need to display such mechanisms of regulation. Here we use the Australian termite Nasutitermes exitiosus as a model to test this prediction for the first time. We used the nutritional geometric framework to investigate the regulation of carbohydrate and protein, as well as the effects on foraging behaviour of protein type and group caste composition and size. Our results support the prediction of nutritional ecology, as termites failed to actively defend a well-defined macronutrient ratio. Termites maintained food collection relatively constant across protein type and group composition, and only appear to vary their collection by avoiding diets too rich in protein.
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Affiliation(s)
- Laure-Anne Poissonnier
- School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, South Australia 5005, Australia; Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse 31062, France.
| | - Stephen J Simpson
- Charles Perkins Centre and School of Biological Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Audrey Dussutour
- Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse 31062, France
| | - Camille Buhl
- School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, South Australia 5005, Australia
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9
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Deans C, Sword GA, Behmer ST. First evidence of protein-carbohydrate regulation in a plant bug (Lygus hesperus). JOURNAL OF INSECT PHYSIOLOGY 2019; 116:118-124. [PMID: 31112715 DOI: 10.1016/j.jinsphys.2019.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/02/2019] [Accepted: 05/17/2019] [Indexed: 06/09/2023]
Abstract
Lygus bugs are highly polyphagous piercing/sucking insects found throughout North America. Collectively, they have been reported to feed on over 330 plant species (one of the broadest host range ever documented for a group of insects); they also feed on many economically important crops. Despite its prevalence across North America and status as a common pest in many agroecosystems, very little is known about how Lygus bugs regulate their intake of nutrients. In reality, little is known about nutrient regulation for most hemipterans, specifically non-phloem feeding species in the suborder Heteroptera. This likely reflects difficulties in developing adequate artificial diets for insects with piercing/sucking mouthparts. There is, however, an artificial diet for L. hersperus, and in this study we modified it and performed choice and no-choice experiments to determine how L. hesperus regulates its intake of two macronutrients - protein (p) and carbohydrates (c) - that are tightly linked to survival and performance in other insect herbivores. In choice experiments L. hesperus was allowed to select between two foods with different protein:carbohydrate ratios. We documented strong regulation for protein and carbohydrates, with late instar nymphs selecting a slightly protein-biased intake target (protein-carbohydrate ratio = 1.5:1). We also performed no-choice experiments, where nymphs were restricted to a single food. Here, the protein-carbohydrate ratio of their food had a strong impact on survival, which was highest for nymphs reared on the treatment with a protein-carbohydrate ratio closest to the self-selected intake target (determined by the choice experiments), but no significant impact on developmental time or mass gain. Our data are the first of their kind for a non-phloem feeding hemipteran and provide a starting point for more broadly understanding and further investigating the nutritional ecology/physiology of Lygus bugs. Our study also provides a framework for exploring nutrient regulation in other hemipterans and for optimizing artificial diets for piercing/sucking insects, especially heteropterans.
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Affiliation(s)
- Carrie Deans
- Texas A&M University, College Station, TX 77843, United States; University of Minnesota, St. Paul, MN 55108, United States
| | - Gregory A Sword
- Texas A&M University, College Station, TX 77843, United States
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10
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Acquiring nutrients from tree leaves: effects of leaf maturity and development type on a generalist caterpillar. Oecologia 2017; 184:59-73. [PMID: 28342011 DOI: 10.1007/s00442-017-3854-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 03/15/2017] [Indexed: 10/19/2022]
Abstract
The rapid growth and prolific reproduction of many insect herbivores depend on the efficiencies and rates with which they acquire nutrients from their host plants. However, little is known about how nutrient assimilation efficiencies are affected by leaf maturation or how they vary between plant species. Recent work showed that leaf maturation can greatly decrease the protein assimilation efficiency (PAE) of Lymantria dispar caterpillars on some tree species, but not on species in the willow family (Salicaceae). One trait of many species in the Salicaceae that potentially affects PAE is the continuous (or "indeterminate") development of leaves throughout the growing season. To improve our understanding of the temporal and developmental patterns of nutrient availability for tree-feeding insects, this study tested two hypotheses: nutrients (protein and carbohydrate) are more efficiently assimilated from immature than mature leaves, and, following leaf maturation, nutrients are more efficiently assimilated from indeterminate than determinate tree species. The nutritional physiology and growth of a generalist caterpillar (L. dispar) were measured on five determinate and five indeterminate tree species while their leaves were immature and again after they were mature. In support of the first hypothesis, caterpillars that fed on immature leaves had significantly higher PAE and carbohydrate assimilation efficiency (CAE), as well as higher protein assimilation rates and growth rates, than larvae that fed on mature leaves. Contrary to the second hypothesis, caterpillars that fed on mature indeterminate tree leaves did not have higher PAE than those that fed on mature determinate leaves, while CAE differed by only 3% between tree development types. Instead, "high-PAE" and "low-PAE" tree species were found across taxonomic and development categories. The results of this study emphasize the importance of physiological mechanisms, such as nutrient assimilation efficiency, to explain the large variation in host plant quality for insect herbivores.
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11
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Deans CA, Sword GA, Behmer ST. Revisiting macronutrient regulation in the polyphagous herbivore Helicoverpa zea (Lepidoptera: Noctuidae): New insights via nutritional geometry. JOURNAL OF INSECT PHYSIOLOGY 2015; 81:21-27. [PMID: 26141409 DOI: 10.1016/j.jinsphys.2015.06.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/27/2015] [Accepted: 06/29/2015] [Indexed: 06/04/2023]
Abstract
Insect herbivores that ingest protein and carbohydrates in physiologically-optimal proportions and concentrations show superior performance and fitness. The first-ever study of protein-carbohydrate regulation in an insect herbivore was performed using the polyphagous agricultural pest Helicoverpa zea. In that study, experimental final instar caterpillars were presented two diets - one containing protein but no carbohydrates, the other containing carbohydrates but no protein - and allowed to self-select their protein-carbohydrate intake. The results showed that H. zea selected a diet with a protein-to-carbohydrate (p:c) ratio of 4:1. At about this same time, the geometric framework (GF) for the study of nutrition was introduced. The GF is now established as the most rigorous means to study nutrient regulation (in any animal). It has been used to study protein-carbohydrate regulation in several lepidopteran species, which exhibit a range of self-selected p:c ratios between 0.8 and 1.5. Given the economic importance of H. zea, and it is extremely protein-biased p:c ratio of 4:1 relative to those reported for other lepidopterans, we decided to revisit its protein-carbohydrate regulation. Our results, using the experimental approach of the GF, show that H. zea larvae self-select a p:c ratio of 1.6:1. This p:c ratio strongly matches that of its close relative, Heliothis virescens, and is more consistent with self-selected p:c ratios reported for other lepidopterans. Having accurate protein and carbohydrate regulation information for an insect herbivore pest such as H. zea is valuable for two reasons. First, it can be used to better understand feeding patterns in the field, which might lead to enhanced management. Second, it will allow researchers to develop rearing diets that more accurately reflect larval nutritional needs, which has important implications for resistance bioassays and other measures of physiological stress.
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Affiliation(s)
- Carrie A Deans
- Department of Entomology, Texas A&M University, TAMU 2475, College Station, TX 77843, USA.
| | - Gregory A Sword
- Department of Entomology, Texas A&M University, TAMU 2475, College Station, TX 77843, USA; Ecology and Evolutionary Biology Program, Texas A&M University, TAMU 2475, College Station, TX 77843, USA
| | - Spencer T Behmer
- Department of Entomology, Texas A&M University, TAMU 2475, College Station, TX 77843, USA; Ecology and Evolutionary Biology Program, Texas A&M University, TAMU 2475, College Station, TX 77843, USA
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12
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Evenden ML, Whitehouse CM, Jones BC. Resource Allocation to Flight in an Outbreaking Forest Defoliator Malacosoma disstria. ENVIRONMENTAL ENTOMOLOGY 2015; 44:835-845. [PMID: 26313990 DOI: 10.1093/ee/nvv055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 03/10/2015] [Indexed: 06/04/2023]
Abstract
Allocation of larval nutrients affects adult life history traits in insects. This study assessed the effect of moth age and wing loading on flight capacity in an outbreaking forest lepidopteran, Malacosoma disstria Hübner . Insects were collected from high and low density populations after larval feeding, and flight capacity was tested directly with flight mills and indirectly through the allometric relationship between wing area and body size. Insects from these same populations collected as eggs and fed with a synthetic diet in the laboratory were tested in a separate experiment. Male moth propensity to fly increased with wing loading only when moths were collected as pupae after feeding in the field at high population densities. Moth age and wing loading did not affect the distance flown by male moths in any of the population density-nutrient regime combinations tested. Energy use increased with flight distance in both experiments. The slope of the allometric relationship between wing area and body mass did not differ from isometry when moths were collected as pupae after feeding at low and high population densities in the field. The slope of this relationship was steeper for males collected from high than low population densities. There was no allometric relationship between wing area and body mass of moths collected from these same populations as eggs and fed ad libitum in the laboratory as larvae. The results suggest that male M. disstria can allocate resources to different life history traits in response to differences in population density.
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Affiliation(s)
- M L Evenden
- Department of Biological Sciences, University of Alberta, AB T6G 2E9, Canada.
| | - C M Whitehouse
- Department of Biological Sciences, University of Alberta, AB T6G 2E9, Canada. Present address: Alberta Environment and Sustainable Resource Development, Operations Division, Peace River, AB T8S 1T4, Canada
| | - B C Jones
- Department of Biological Sciences, University of Alberta, AB T6G 2E9, Canada. Present address: Alberta Environment and Sustainable Resource Development, Operations Division, Calgary, AB T3L 1S4, Canada
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Geometry of nutrition in field studies: an illustration using wild primates. Oecologia 2014; 177:223-34. [DOI: 10.1007/s00442-014-3142-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 11/03/2014] [Indexed: 10/24/2022]
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Lihoreau M, Buhl C, Charleston MA, Sword GA, Raubenheimer D, Simpson SJ. Modelling nutrition across organizational levels: from individuals to superorganisms. JOURNAL OF INSECT PHYSIOLOGY 2014; 69:2-11. [PMID: 24681322 DOI: 10.1016/j.jinsphys.2014.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 03/06/2014] [Accepted: 03/12/2014] [Indexed: 06/03/2023]
Abstract
The Geometric Framework for nutrition has been increasingly used to describe how individual animals regulate their intake of multiple nutrients to maintain target physiological states maximizing growth and reproduction. However, only a few studies have considered the potential influences of the social context in which these nutritional decisions are made. Social insects, for instance, have evolved extreme levels of nutritional interdependence in which food collection, processing, storage and disposal are performed by different individuals with different nutritional needs. These social interactions considerably complicate nutrition and raise the question of how nutrient regulation is achieved at multiple organizational levels, by individuals and groups. Here, we explore the connections between individual- and collective-level nutrition by developing a modelling framework integrating concepts of nutritional geometry into individual-based models. Using this approach, we investigate how simple nutritional interactions between individuals can mediate a range of emergent collective-level phenomena in social arthropods (insects and spiders) and provide examples of novel and empirically testable predictions. We discuss how our approach could be expanded to a wider range of species and social systems.
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Affiliation(s)
- Mathieu Lihoreau
- The Charles Perkins Centre, The University of Sydney, NSW 2006, Australia; School of Biological Sciences, The University of Sydney, NSW 2006, Australia; Centre National de la Recherche Scientifique (CNRS), Centre de Recherches sur la Cognition Animale, Toulouse 31062, France; Université de Toulouse (UPS), Centre de Recherches sur la Cognition Animale, Toulouse 31062, France.
| | - Camille Buhl
- The Charles Perkins Centre, The University of Sydney, NSW 2006, Australia; School of Biological Sciences, The University of Sydney, NSW 2006, Australia
| | - Michael A Charleston
- School of Information Technologies, The University of Sydney, NSW 2006, Australia
| | - Gregory A Sword
- Department of Entomology, Interdisciplinary Faculty of Ecology and Evolutionary Biology, Texas A&M University, TX 77843-2475, USA
| | - David Raubenheimer
- The Charles Perkins Centre, The University of Sydney, NSW 2006, Australia; School of Biological Sciences, The University of Sydney, NSW 2006, Australia; Faculty of Veterinary Science, The University of Sydney, NSW 2006, Australia
| | - Stephen J Simpson
- The Charles Perkins Centre, The University of Sydney, NSW 2006, Australia; School of Biological Sciences, The University of Sydney, NSW 2006, Australia
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Anthropogenic changes in sodium affect neural and muscle development in butterflies. Proc Natl Acad Sci U S A 2014; 111:10221-6. [PMID: 24927579 DOI: 10.1073/pnas.1323607111] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The development of organisms is changing drastically because of anthropogenic changes in once-limited nutrients. Although the importance of changing macronutrients, such as nitrogen and phosphorus, is well-established, it is less clear how anthropogenic changes in micronutrients will affect organismal development, potentially changing dynamics of selection. We use butterflies as a study system to test whether changes in sodium availability due to road salt runoff have significant effects on the development of sodium-limited traits, such as neural and muscle tissue. We first document how road salt runoff can elevate sodium concentrations in the tissue of some plant groups by 1.5-30 times. Using monarch butterflies reared on roadside- and prairie-collected milkweed, we then show that road salt runoff can result in increased muscle mass (in males) and neural investment (in females). Finally, we use an artificial diet manipulation in cabbage white butterflies to show that variation in sodium chloride per se positively affects male flight muscle and female brain size. Variation in sodium not only has different effects depending on sex, but also can have opposing effects on the same tissue: across both species, males increase investment in flight muscle with increasing sodium, whereas females show the opposite pattern. Taken together, our results show that anthropogenic changes in sodium availability can affect the development of traits in roadside-feeding herbivores. This research suggests that changing micronutrient availability could alter selection on foraging behavior for some roadside-developing invertebrates.
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Roeder KA, Behmer ST. Lifetime consequences of food protein-carbohydrate content for an insect herbivore. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12262] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Karl A. Roeder
- Department of Entomology; Texas A&M University; College Station TX 77843 USA
- Department of Biology; University of Oklahoma; Norman OK 73019 USA
| | - Spencer T. Behmer
- Department of Entomology; Texas A&M University; College Station TX 77843 USA
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17
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Dietary mixing within the crown of a deciduous conifer enhances the fitness of a specialist sawfly. Anim Behav 2012. [DOI: 10.1016/j.anbehav.2012.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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McClure M, Morcos L, Despland E. Collective choice of a higher-protein food source by gregarious caterpillars occurs through differences in exploration. Behav Ecol 2012. [DOI: 10.1093/beheco/ars141] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Lee KP. Sex-specific differences in nutrient regulation in a capital breeding caterpillar, Spodoptera litura (Fabricius). JOURNAL OF INSECT PHYSIOLOGY 2010; 56:1685-1695. [PMID: 20619268 DOI: 10.1016/j.jinsphys.2010.06.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 06/25/2010] [Accepted: 06/29/2010] [Indexed: 05/29/2023]
Abstract
Nutrient requirements by male and female insects are likely to differ, but relatively little is known regarding how sexes differ in their regulation of macronutrient acquisition. The present study reports the results from a laboratory experiment in which behavioural and physiological components of nutrient regulation were compared between male and female caterpillars of Spodoptera litura (Fabricius). When provided with choices between two nutritionally complementary foods (one is a protein-biased diet and the other a carbohydrate-biased diet), both males and females adjusted their food selection to defend an intake target. However, the composition of diet preferred by the two differed, with females selecting significantly more protein than males with no difference in carbohydrate intake between the two. When confined to single diets with varying mixtures of protein and carbohydrate [P:C ratios, expressed as the percentage of diet by dry mass: protein 42%:carbohydrate 0% (p42:c0), p35:c7, p28:c14, p21:c21, p14:c28, p7:c35], females consumed more macronutrients than did males across on all P:C diets except the extremely carbohydrate-biased diet (p7:c35). Under both choice and no-choice feeding condition, such sex differences in nutrient intake were not expressed until late in the feeding stage of the final stadium. Sexes also differed in post-ingestive utilization of ingested nutrients. Females utilized ingested protein for body growth with greater efficiency compared to males, presumably reflecting provisioning their adult needs for protein to develop eggs, whereas males were more efficient at depositing lipids from carbohydrate intake than females.
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Affiliation(s)
- Kwang Pum Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea.
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Colasurdo N, Gélinas Y, Despland E. Larval nutrition affects life history traits in a capital breeding moth. ACTA ACUST UNITED AC 2009; 212:1794-800. [PMID: 19482996 DOI: 10.1242/jeb.027417] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Fitness depends not only on resource uptake but also on the allocation of these resources to various life history functions. This study explores the life-history consequences of larval diet in terms not only of larval performance but also of adult body composition and reproductive traits in the forest tent caterpillar (Malacosoma disstria Hübner). Caterpillars were reared on their preferred tree host, trembling aspen (Populus tremuloides), or on one of three artificial foods: high protein:low carbohydrate, equal protein-to-carbohydrate ratio or low protein:high carbohydrate. Survivorship, larval development rate and adult body size were lowest on the carbohydrate-biased diet and similar on the protein-biased and equal-ratio diets. Fecundity increased with body size but did not otherwise differ between diets. Moths reared on the carbohydrate-biased diet allocated a lower proportion of their mass to the ovaries and more to somatic growth whereas those on equal-ratio and protein-biased diets allocated more to reproductive tissue and less to somatic tissue. These differences in allocation to reproduction arose from differences in the size of eggs, an index of offspring quality. No differences were found in lipid and protein content of female ovaries, accessory glands or somatic tissue, or of the whole body of male moths. The findings show that physiological processes regulate the composition of the different components of the adult body. Diet effects occur as differences in overall body size and in relative allocation to these components. Although lepidopterans can, to a large extent, compensate post-ingestively for nutritionally deficient diets, investment in reproduction vs somatic growth depends on the nutrients available.
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Affiliation(s)
- Nadia Colasurdo
- Biology Department, Concordia University, 7141 Sherbrooke W, Montreal, Quebec, Canada H4B 1R6
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Abstract
The primary reason animals, including insect herbivores, eat is to acquire a mix of nutrients needed to fuel the processes of growth, development, and reproduction. Most insect herbivores strongly regulate their nutrient intake when given the opportunity. When they are restricted to imbalanced diets, they employ regulatory rules that govern the extent to which nutrients occurring in excess or deficit are eaten. Insect herbivores also regularly encounter allelochemicals as they eat, and recent work indicates the effect an allelochemical has on nutrient regulation, and insect herbivore performance, is modified depending on a food's nutrient composition. Comparative studies of nutrient regulation suggest coexisting generalist herbivores occupy unique nutritional feeding niches, and work with pathogens and parasitoids has revealed the manner in which top-down pressures influence patterns of nutrient intake. Insect herbivores regulate their nutrient intake using pre- and postingestive mechanisms, plus learning, and there is evidence that some of these mechanisms are shaped by natural selection.
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Affiliation(s)
- Spencer T Behmer
- Department of Entomology, Texas A&M University, College Station Texas, 77845-2475, USA.
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Major IT, Constabel CP. Functional analysis of the Kunitz trypsin inhibitor family in poplar reveals biochemical diversity and multiplicity in defense against herbivores. PLANT PHYSIOLOGY 2008; 146:888-903. [PMID: 18024557 PMCID: PMC2259082 DOI: 10.1104/pp.107.106229] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Accepted: 11/06/2007] [Indexed: 05/21/2023]
Abstract
We investigated the functional and biochemical variability of Kunitz trypsin inhibitor (KTI) genes of Populus trichocarpa x Populus deltoides. Phylogenetic analysis, expressed sequence tag databases, and western-blot analysis confirmed that these genes belong to a large and diverse gene family with complex expression patterns. Five wound- and herbivore-induced genes representing the diversity of the KTI gene family were selected for functional analysis and shown to produce active KTI proteins in Escherichia coli. These recombinant KTI proteins were all biochemically distinct and showed clear differences in efficacy against trypsin-, chymotrypsin-, and elastase-type proteases, suggesting functional specialization of different members of this gene family. The in vitro stability of the KTIs in the presence of reducing agents and elevated temperature also varied widely, emphasizing the biochemical differences of these proteins. Significantly, the properties of the recombinant KTI proteins were not predictable from primary amino acid sequence data. Proteases in midgut extracts of Malacosoma disstria, a lepidopteran pest of Populus, were strongly inhibited by at least two of the KTI gene products. This study suggests that the large diversity in the poplar (Populus spp.) KTI family is important for biochemical and functional specialization, which may be important in the maintenance of pest resistance in long-lived plants such as poplar.
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Affiliation(s)
- Ian T Major
- Centre for Forest Biology and Department of Biology, University of Victoria, Victoria, BC, Canada
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Babic B, Poisson A, Darwish S, Lacasse J, Merkx-Jacques M, Despland E, Bede JC. Influence of dietary nutritional composition on caterpillar salivary enzyme activity. JOURNAL OF INSECT PHYSIOLOGY 2008; 54:286-296. [PMID: 17997409 DOI: 10.1016/j.jinsphys.2007.09.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Revised: 09/19/2007] [Accepted: 09/28/2007] [Indexed: 05/25/2023]
Abstract
Caterpillars are faced with nutritional challenges when feeding on plants. In addition to harmful secondary metabolites and protein- and water-limitations, tissues may be carbohydrate-rich which may attenuate optimal caterpillar performance. Therefore, caterpillars have multiple strategies to cope with surplus carbohydrates. In this study, we raise the possibility of a pre-ingestive mechanism to metabolically deal with excess dietary sugars. Many Noctuid caterpillars secrete the labial salivary enzyme glucose oxidase (GOX), which oxidizes glucose to hydrogen peroxide and gluconate, a nutritionally unavailable carbohydrate to the insect. Beet armyworm, Spodoptera exigua, larvae were restricted to diets varying in protein to digestible carbohydrate (P:C) ratio (42p:21c; 33p:30c; 21p:42c) and total nutrient concentration (42% and 63%). High mortality and longer developmental time were observed when caterpillars were reared on the C-biased, P-poor diet (21p:42c). As the carbohydrate content of the diet increased, caterpillars egested excess glucose and a diet-dependent difference in assimilated carbohydrates and pupal biomass was not observed, even though caterpillars restricted to the C-biased diet (21p:42c) accumulated greater pupal lipid reserves. Larval labial salivary GOX activity was also diet-dependent and gluconate, the product of GOX activity, was detected in the frass. Unexpectedly, GOX activity was strongly and positively correlated with dietary protein content.
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Affiliation(s)
- Branislav Babic
- Department of Plant Science, McGill University, 21,111 Lakeshore, Ste-Anne-de-Bellevue, Québec, Canada H9X 3V9
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Colasurdo N, Dussutour A, Despland E. Do food protein and carbohydrate content influence the pattern of feeding and the tendency to explore of forest tent caterpillars? JOURNAL OF INSECT PHYSIOLOGY 2007; 53:1160-8. [PMID: 17689556 DOI: 10.1016/j.jinsphys.2007.06.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 06/11/2007] [Accepted: 06/13/2007] [Indexed: 05/16/2023]
Abstract
This study examines whether the ratio of protein to carbohydrate affects the timing of meals and the propensity to explore of forest tent caterpillars (Malacosoma disstria). The behavior of fourth instar caterpillars was observed on three semi-defined artificial diets varying in protein (p)-carbohydrate (c) ratio. These diets were (a) p14:c28, (b) p28:c14, and (c) p35:c7. The probability of initiating feeding at first contact with the food and the duration of the first feeding event did not vary across diets, suggesting not much difference in phagostimulatory power. There was also no difference in the total time spent eating, at rest and in motion between diets. However, the timing and duration of meals varied significantly; more short meals were observed on the carbohydrate-biased diet. The duration of pauses between meals also increased with food protein content. Furthermore, caterpillars on the carbohydrate-biased diet were more likely to leave the trail leading to the known food source and to discover a second food source, suggesting that protein deprivation promotes exploration. These findings shed insight into the physiological responses to protein and carbohydrate ingestion and demonstrate how post-ingestive effects can favor consumption of foods containing protein without invoking an explicit mechanism of independent nutrient regulation, but simply by influencing the pattern of feeding and the propensity to explore.
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Affiliation(s)
- Nadia Colasurdo
- Biology Department, Concordia University, 7141 Sherbrooke W, Montreal, Que., Canada H4B 1R6
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Bede JC, McNeil JN, Tobe SS. The role of neuropeptides in caterpillar nutritional ecology. Peptides 2007; 28:185-96. [PMID: 17161504 DOI: 10.1016/j.peptides.2006.08.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 08/10/2006] [Accepted: 08/10/2006] [Indexed: 11/17/2022]
Abstract
Plant diet strongly impacts the fitness of insect herbivores. Immediately, we think of plant defensive compounds that may act as feeding deterrents or toxins. We are, probably, less aware that plants also influence insect growth and fecundity through their nutritional quality. However, most herbivores respond to their environment and select the diet which optimizes their growth and development. This regulation of nutritional balance may occur on many levels: through selecting and ingesting appropriate plant tissue and nutrient digestion, absorption and utilization. Here, we review evidence of how nutritional requirements, particularly leaf protein to digestible carbohydrate ratios, affect caterpillar herbivores. We propose a model where midgut endocrine cells assess and integrate hemolymph nutritional status and gut content and release peptides which influence digestive processes. Understanding the effects of diet on the insect herbivore is essential for the rational design and implementation of sustainable pest management practices.
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Affiliation(s)
- Jacqueline C Bede
- Department of Plant Science, McGill University, Ste-Anne-de-Bellevue, Que., Canada H9X 3V9.
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