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Vasquez A, Alaniz A, Dearth R, Kariyat R. Continuous mowing differentially affects floral defenses in the noxious and invasive weed Solanum elaeagnifolium in its native range. Sci Rep 2024; 14:8133. [PMID: 38584186 PMCID: PMC10999409 DOI: 10.1038/s41598-024-58672-w] [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: 11/21/2023] [Accepted: 04/02/2024] [Indexed: 04/09/2024] Open
Abstract
In weeds, disturbance has been found to affect life history traits and mediate trophic interactions. In urban landscapes, mowing is an important disturbance, and we previously showed that continuous mowing leads to enhanced fitness and defense traits in Solanum elaeagnifolium, Silverleaf Nightshade (SLN). However, most studies have been focused on foliar defenses, ignoring floral defenses. In this study we examined whether continuous mowing affected floral defenses in SLN using mowed and unmowed populations in South Texas, their native range. We found flowers of mowed SLN plants larger but lighter than unmowed plants. Additionally, flowers on plants that were mowed frequently were both heavier and larger. Mowed plants had higher spine density and consequently unmowed flowers had higher herbivore damage. Additionally, early instar Manduca sexta fed on mowed flower-based artificial diets showed no difference in mass than the control and unmowed; however, later instars caterpillars on unmowed diets gained significantly more mass than the mowed treatment and control. Mowed plants had higher spine density which may shed light on why unmowed flowers experienced higher herbivore damage. We found caterpillars fed on high mowing frequency diets were heavier than those on low mowing frequency diets. Collectively, we show that mowing compromises floral traits and enhances plant defenses against herbivores and should be accounted for in management.
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Affiliation(s)
- Alejandro Vasquez
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Alexa Alaniz
- Department of Biology, The University of Texas Rio Grande Valley, Edinburg, TX, 78504, USA
| | - Robert Dearth
- Department of Biology, The University of Texas Rio Grande Valley, Edinburg, TX, 78504, USA
| | - Rupesh Kariyat
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR, 72701, USA.
- Department of Biology, The University of Texas Rio Grande Valley, Edinburg, TX, 78504, USA.
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Fajemisin A, Racelis A, Kariyat R. Cascading Effects of Cover Crops on the Subsequent Cash Crop Defense against the Polyphagous Herbivore Fall Armyworm ( Spodoptera frugiperda). INSECTS 2023; 14:177. [PMID: 36835746 PMCID: PMC9959575 DOI: 10.3390/insects14020177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/02/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Recent studies have started to show that the benefits of cover crops can cascade to the cash crop growing seasons. However, the impact of cover crops on the subsequent cash crop defense against herbivores is not well understood. To test this, we conducted a field and laboratory study to assess the possible cascading effects of cover crops such as Vigna unguiculata, Sorghum drummondii, Raphanus sativus, and Crotalaria juncea on the subsequent cash crop (Sorghum bicolor) defense against the notorious polyphagous herbivore fall armyworm (Spodoptera frugiperda) across three farms in the Lower Rio Grande Valley. Our field and laboratory studies showed that the cash crop planted in the cover crop treatment differentially affected S. frugiperda. More specifically, we found that cover crops have positive effects on the growth and development of S. frugiperda on the subsequent cash crop, including both larval and pupal parameters. However, our experiments on physical and chemical defenses in cash crops failed to show any significant differences between cover and control. Collectively, our results add an additional line of evidence on the effects of cover crops on pest dynamics outside the cash crop season, a key consideration for the selection and management of cover crops and cash crops, whose underlying mechanisms need to be examined further.
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Affiliation(s)
- Adegboyega Fajemisin
- School of Earth Environmental and Marine Sciences, University of Texas Rio Grande Valley, Edinburg, TX 78539, USA
| | - Alexis Racelis
- School of Earth Environmental and Marine Sciences, University of Texas Rio Grande Valley, Edinburg, TX 78539, USA
| | - Rupesh Kariyat
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
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Pocius VM, Cibotti S, Ray S, Ankoma-Darko O, McCartney NB, Schilder RJ, Ali JG. Impacts of larval host plant species on dispersal traits and free-flight energetics of adult butterflies. Commun Biol 2022; 5:469. [PMID: 35577926 PMCID: PMC9110344 DOI: 10.1038/s42003-022-03396-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 04/22/2022] [Indexed: 12/03/2022] Open
Abstract
Animals derive resources from their diet and allocate them to organismal functions such as growth, maintenance, reproduction, and dispersal. How variation in diet quality can affect resource allocation to life-history traits, in particular those important to locomotion and dispersal, is poorly understood. We hypothesize that, particularly for specialist herbivore insects that are in co-evolutionary arms races with host plants, changes in host plant will impact performance. From their coevolutionary arms-race with plants, to a complex migratory life history, Monarch butterflies are among the most iconic insect species worldwide. Population declines initiated international conservation efforts involving the replanting of a variety of milkweed species. However, this practice was implemented with little regard for how diverse defensive chemistry of milkweeds experienced by monarch larvae may affect adult fitness traits. We report that adult flight muscle investment, flight energetics, and maintenance costs depend on the host plant species of larvae, and correlate with concentration of milkweed-derived cardenolides sequestered by adults. Our findings indicate host plant species can impact monarchs by affecting fuel requirements for flight. The growth of muscle and flight performance in monarch butterflies is influenced by the plant species the larvae grow on.
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Affiliation(s)
- Victoria M Pocius
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, USA
| | - Staci Cibotti
- Department of Entomology, The Pennsylvania State University, University Park, PA, USA
| | - Swayamjit Ray
- Department of Plant Pathology, Cornell University, Ithaca, NY, USA
| | - Obenewa Ankoma-Darko
- Department of Entomology, The Pennsylvania State University, University Park, PA, USA
| | - Nathaniel B McCartney
- Department of Entomology, The Pennsylvania State University, University Park, PA, USA
| | - Rudolf J Schilder
- Department of Entomology, The Pennsylvania State University, University Park, PA, USA.
| | - Jared G Ali
- Department of Entomology, The Pennsylvania State University, University Park, PA, USA.
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Jacobsen DJ. Manduca sexta experience high parasitoid pressures in the field but minor fitness costs of consuming plant secondary compounds. Ecol Evol 2021; 11:13884-13897. [PMID: 34707825 PMCID: PMC8525118 DOI: 10.1002/ece3.8094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/23/2021] [Accepted: 08/26/2021] [Indexed: 11/08/2022] Open
Abstract
Plant-herbivore coevolutionary interactions have led to a range of plant defenses that minimize insect damage and a suite of counter adaptations that allow herbivores to feed on defended plants. Consuming plant secondary compounds results in herbivore growth and developmental costs but can have beneficial effects such as deterrence or harm of parasitoid enemies. Therefore, the role of secondary compounds on herbivore fitness must be considered in the context of the abundance and level of harm from natural enemies and the costs herbivores incur feeding on plant secondary compounds.In this study, I combined field measurements of Cotesia congregata wasp parasitism pressure with detailed measurements of the costs of plant secondary compounds across developmental stages in the herbivore host, Manduca sexta.I show that C. congregata parasitoids exert large negative selective pressures, killing 31%-57% of M. sexta larvae in the field. Manduca sexta developed fastest during instars most at risk for parasitoid oviposition but growth was slowed by consumption of plant secondary compounds. The negative effects of consuming plant secondary compounds as larvae influenced adult size traits but there were no immune, survival, or fecundity costs.These results suggest that developmental costs experienced by M. sexta herbivores consuming defensive compounds are minor in comparison to the strong negative survival pressures from abundant parasitoid enemies.
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Uyi O, Keller JA, Swackhamer E, Hoover K. Performance and host association of spotted lanternfly (Lycorma delicatula) among common woody ornamentals. Sci Rep 2021; 11:15774. [PMID: 34349195 PMCID: PMC8338946 DOI: 10.1038/s41598-021-95376-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 07/26/2021] [Indexed: 11/16/2022] Open
Abstract
Lycorma delicatula (spotted lanternfly) has a broad host range with a strong preference for the invasive host plant from its native range, tree of heaven (Ailanthus altissima); it had long been speculated that L. delicatula could not develop or reproduce without access to tree of heaven. In 2019, we found that this assumption was incorrect, but fitness was reduced in the absence of A. altissima in that the number of egg masses laid was dramatically fewer for insects reared on suitable non-A. altissima host plants that had recently been established. We hypothesized that longer established, larger trees (of the same species) would improve the fitness of L. delicatula in the absence of tree of heaven. In spring 2020, we examined insect performance with and without access to A. altissima by tracking development, survival, host tree association and oviposition in large enclosures with trees planted two years prior to the study. Each enclosure included one each of Juglans nigra, Salix babylonica and Acer saccharinum along with either one A. altissima or one Betula nigra; these trees had twice the diameter of the same trees the previous year. We reared nymphs with and without access to A. altissima, released them into the corresponding large enclosures as third instars, and monitored them from early July 2020 through November 2020. We also determined whether lack of access to A. altissima by parents of L. delicatula have any fitness effects on offspring performance. To ensure adequate adult populations for comparing fecundity between treatments, third instars were released into the multi-tree enclosures due to high mortality in earlier instars that occurred in a similar study in 2019. Insect survival was higher and development faster with access to A. altissima. Third and fourth instar nymphs were most frequently observed on A. altissima when it was present, while adults were equally associated with A. saccharinum and A. altissima. In the absence of A. altissima, nymphs were most frequently found on S. babylonica, while adults were most often on A. saccharinum. Females with access to A. altissima deposited nearly 7-fold more egg masses than those without access to A. altissima, which is consistent with the difference in egg mass numbers between the two treatments the previous year; thus, our hypothesis was rejected. The offspring of parents that had been reared without access to A. altissima showed similar survival and development time from egg to adult as offspring from parents that never had access to A. altissima. These findings suggest that managers need to be aware that even in the absence of A. altissima in the landscape, several hardwood host trees can be utilized by L. delicatula to develop and reproduce, but fitness without A. altissima is likely to still be reduced.
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Affiliation(s)
- Osariyekemwen Uyi
- Department of Entomology, Pennsylvania State University, 501 ASI Building, University Park, PA, 16802, USA.,Department of Animal and Environmental Biology, University of Benin, P.M.B. 1154, Benin City, Nigeria
| | - Joseph A Keller
- Department of Entomology, Pennsylvania State University, 501 ASI Building, University Park, PA, 16802, USA
| | - Emelie Swackhamer
- Horticulture Educator, Penn State Extension Montgomery, Collegeville, PA, 19426, USA
| | - Kelli Hoover
- Department of Entomology, Pennsylvania State University, 501 ASI Building, University Park, PA, 16802, USA.
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Uyi O, Keller JA, Johnson A, Long D, Walsh B, Hoover K. Spotted Lanternfly (Hemiptera: Fulgoridae) Can Complete Development and Reproduce Without Access to the Preferred Host, Ailanthus altissima. ENVIRONMENTAL ENTOMOLOGY 2020; 49:1185-1190. [PMID: 32725170 DOI: 10.1093/ee/nvaa083] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Indexed: 06/11/2023]
Abstract
Despite its broad host range, the spotted lanternfly Lycorma delicatula (White), is known to have a marked preference for Ailanthus altissima. However, whether this polyphagous phloem feeder can complete its life cycle in the absence of A. altissima is unknown. We examined the performance of L. delicatula with and without access to A. altissima by tracking development, survival, host tree species association, and oviposition in large enclosures planted with Salix babylonica and Acer saccharinum along with either A. altissima or Betula nigra. We monitored enclosures from late May 2019 through June 2020. Lycorma delicatula survival was slightly higher in enclosures with A. altissima and 50% of individuals in A. altissima enclosures reached the adult stage ~6.5 d earlier than in enclosures without A. altissima. In the presence of A. altissima, nymphs were most frequently observed on this host while adults were found at similar frequencies on A. altissima and A. saccharinum. In the absence of A. altissima, nymphs were most frequently associated with S. babylonica and A. saccharinum, while adults were most often found on A. saccharinum. Females laid a total of 46 and 6 egg masses in enclosures with and without A. altissima, respectively, before freezing temperatures killed the remaining adults. The proportion of eggs that hatched per egg mass did not differ between treatments. Although L. delicatula can complete development and reproduce on other host species without access to A. altissima, fitness was reduced. These findings have implications for management that relies exclusively on treatment of A. altissima.
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Affiliation(s)
- Osariyekemwen Uyi
- Department of Entomology, Pennsylvania State University, University Park, PA
- Department of Animal and Environmental Biology, University of Benin, Benin City, Nigeria
| | - Joseph A Keller
- Department of Entomology, Pennsylvania State University, University Park, PA
| | - Anne Johnson
- Department of Entomology, Pennsylvania State University, University Park, PA
| | - David Long
- Department of Entomology, Pennsylvania State University, University Park, PA
| | - Brian Walsh
- Department of Entomology, Pennsylvania State University, University Park, PA
| | - Kelli Hoover
- Department of Entomology, Pennsylvania State University, University Park, PA
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Uyi OO, Zachariades C, Heshula LU, Hill MP. Developmental and reproductive performance of a specialist herbivore depend on seasonality of, and light conditions experienced by, the host plant. PLoS One 2018; 13:e0190700. [PMID: 29304104 PMCID: PMC5755886 DOI: 10.1371/journal.pone.0190700] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 12/19/2017] [Indexed: 11/23/2022] Open
Abstract
Host plant phenology (as influenced by seasonality) and light-mediated changes in the phenotypic and phytochemical properties of leaves have been hypothesised to equivocally influence insect herbivore performance. Here, we examined the effects of seasonality, through host plant phenology (late growth-season = autumn vs flowering-season = winter) and light environment (shade vs full-sun habitat) on the leaf characteristics of the invasive alien plant, Chromolaena odorata. In addition, the performance of a specialist folivore, Pareuchaetes insulata, feeding on leaves obtained from both shaded and full-sun habitats during autumn and winter, was evaluated over two generations. Foliar nitrogen and magnesium contents were generally higher in shaded plants with much higher levels during winter. Leaf water content was higher in shaded and in autumn plants. Total non-structural carbohydrate (TNC) and phosphorus contents did not differ as a function of season, but were higher in shaded foliage compared to full-sun leaves. Leaf toughness was noticeably higher on plants growing in full-sun during winter. With the exception of shaded leaves in autumn that supported the best performance [fastest development, heaviest pupal mass, and highest growth rate and Host Suitability Index (HSI) score], full-sun foliage in autumn surprisingly also supported an improved performance of the moth compared to shaded or full-sun leaves in winter. Our findings suggest that shaded and autumn foliage are nutritionally more suitable for the growth and reproduction of P. insulata. However, the heavier pupal mass, increased number of eggs and higher HSI score in individuals that fed on full-sun foliage in autumn compared to their counterparts that fed on shaded or full-sun foliage in winter suggest that full-sun foliage during autumn is also a suitable food source for larvae of the moth. In sum, our study demonstrates that seasonal and light-modulated changes in leaf characteristics can affect insect folivore performance in ways that are not linear.
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Affiliation(s)
- Osariyekemwen O. Uyi
- Department of Zoology and Entomology, University of Fort Hare, Alice, South Africa
- Department of Animal and Environmental Biology, University of Benin, Benin City, Nigeria
- * E-mail:
| | - Costas Zachariades
- ARC–Plant Protection Research Institute, Cedara, South Africa
- School of Life Sciences, University of KwaZulu-Natal, Scottsville, South Africa
| | - Lelethu U. Heshula
- Department of Zoology and Entomology, University of Fort Hare, Alice, South Africa
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | - Martin P. Hill
- Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
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Kariyat RR, Smith JD, Stephenson AG, De Moraes CM, Mescher MC. Non-glandular trichomes of Solanum carolinense deter feeding by Manduca sexta caterpillars and cause damage to the gut peritrophic matrix. Proc Biol Sci 2017; 284:20162323. [PMID: 28228510 PMCID: PMC5326521 DOI: 10.1098/rspb.2016.2323] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/02/2017] [Indexed: 01/15/2023] Open
Abstract
Plant trichomes constitute a first line of defence against insect herbivores. The pre- and post-ingestive defensive functions of glandular trichomes are well documented and include direct toxicity, adhesion, antinutrition and defence gene induction. By contrast, the defensive functions of non-glandular trichomes are less well characterized, although these structures are thought to serve as physical barriers that impede herbivore feeding and movement. We experimentally varied the density of stellate non-glandular trichomes in several ways to explore their pre- and post-ingestive effects on herbivores. Larvae of Manduca sexta (Sphingidae) initiated feeding faster and gained more weight on Solanum carolinense (Solanaceae) leaves having lower trichome densities (or experimentally removed trichomes) than on leaves having higher trichome densities. Adding trichomes to artificial diet also deterred feeding and adversely affected caterpillar growth relative to controls. Scanning electron and light microscopy revealed that the ingestion of stellate trichomes by M. sexta caterpillars caused extensive damage to the peritrophic membrane, a gut lining that is essential to digestion and pathogen isolation. These findings suggest that, in addition to acting as a physical barrier to deter feeding, trichomes can inhibit caterpillar growth and development via post-ingestive effects.
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Affiliation(s)
- Rupesh R Kariyat
- Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092 Zurich, Switzerland
| | - Jason D Smith
- Department of Biology, Dickinson College, Carlisle, PA 17013, USA
| | - Andrew G Stephenson
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Consuelo M De Moraes
- Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092 Zurich, Switzerland
| | - Mark C Mescher
- Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092 Zurich, Switzerland
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