Biology subjects

Groves, R.

Publications and source records attributed to Groves, R..

3 recordsLinked to original sources

bioRxiv2022

Evidence of hard-selective sweeps suggest independent adaptation to insecticides in Colorado potato beetle (Coleoptera: Chrysomelidae) populations

Pesticide resistance provides one of the best examples of rapid evolution to environmental change. The Colorado potato beetle has a long and noteworthy history as a super-pest due to its ability to repeatedly develop resistance to novel insecticides and rapidly expand its geographic and host plant range. Here, we investigate regional differences in demography, recombination and selection using whole genome resequencing data from two highly resistant CPB populations in the United States (Hancock, Wisconsin and Long Island, New York). Demographic reconstruction corroborates historical records for a single pest origin during the colonization of the Midwestern and Eastern United States in the mid-to late-19th century and suggests that the effective population size might be higher in Long Island, NY than Hancock, WI despite contemporary potato acreage of Wisconsin being far greater. Population-based recombination maps show similar background recombination rates between these populations, as well as overlapping regions of low recombination that intersect with important metabolic detoxification genes. In both populations, we find compelling evidence for hard selective sweeps linked to insecticide resistance with multiple sweeps involving genes associated with xenobiotic metabolism, stress response, and defensive chemistry. Notably, only two candidate insecticide resistance genes are shared among both populations, but both appear to be independent hard selective sweep events. This suggests that repeated, rapid, and independent evolution of genes may underlie CPBs pest status among geographically distinct populations.

evolutionary biology↗

bioRxiv2018

Transcriptomic analysis reveals similarities in genetic activation of detoxification mechanisms resulting from imidacloprid and chlorothalonil exposure

The Colorado potato beetle, Leptinotarsa decemlineata (Say), is an agricultural pest of commercial potatoes in parts of North America, Europe, and Asia. Plant protection strategies within this geographic range employ a variety of pesticides to combat not only the insect, but also plant pathogens. Previous research has shown that field populations of Leptinotarsa decemlineata have a chronological history of resistance development to a suite of insecticides, including the Group 4A neonicotinoids. The aim of this study is to contextualize the transcriptomic response of Leptinotarsa decemlineata when exposed to the neonicotinoid insecticide imidacloprid, or the fungicides boscalid or chlorothalonil, in order to determine whether these compounds induce similar detoxification mechanisms. We found that chlorothalonil and imidacloprid induced similar patterns of transcript expression, including the up-regulation of a cytochrome p450 and a UDP-glucuronosyltransferase transcript, which are often associated with xenobiotic metabolism. Further, transcriptomic responses varied among individuals within the same treatment group, suggesting individual insects responses vary within a population and may cope with chemical stressors in a variety of manners. These results further our understanding of the mechanisms involved in insecticide resistance in Leptinotarsa decemlineata.\n\nAuthor Contribution StatementConceived and designed the experiments: JC, CB, RLG. Performed the experiments: JC, BSS. Analyzed the data: JC, BSS. Wrote the paper: JC, BSS, RLG.

genetics↗

bioRxiv2018

Agricultural fungicides inadvertently influence the fitness of Colorado potato beetles, Leptinotarsa decemlineata, and their susceptibility to insecticides

The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is an agricultural pest of solanaceous crops which has developed insecticide resistance at an alarming rate. Up to this point, little consideration has been given to unintended, or inadvertent effects that non-insecticide xenobiotics may have on insecticide susceptibility in L. decemlineata. Fungicides, such as chlorothalonil and boscalid, are often used to control fungal pathogens in potato fields and are applied at regular intervals when L. decemlineata populations are present in the crop. In order to determine whether fungicide use may be associated with elevated levels of insecticide resistance in L. decemlineata, we examined phenotypic responses in L. decemlineata to the fungicides chlorothalonil and boscalid. Using enzymatic and transcript abundance investigations we also examined modes of molecular detoxification in response to both insecticide (imidacloprid) and fungicide (boscalid and chlorothalonil) application to more specifically determine if fungicides and insecticides induce similar metabolic detoxification mechanisms. Both chlorothalonil and boscalid exposure induced a phenotypic, enzymatic and transcript response in L. decemlineata which correlates with known mechanisms of insecticide resistance.\n\nKey MessagesO_LIPrior-exposure to a fungicidal application changes the phenotypic response of Leptinotarsa decemlineata to the insecticide imidacloprid\nC_LIO_LIBoth a fungicide and insecticide application activates similar molecular mechanisms of detoxification in Leptinotarsa decemlineata\nC_LIO_LIFungicidal xenobiotics may contribute to insecticide resistance in Leptinotarsa decemlineata\nC_LI\n\nAuthor Contribution StatementJC, SS, CB, AH, and RG conceived and designed research. JC, AC, DA, TD, and BS conducted experiments. JC and AC analyzed data. JC and RG wrote the manuscript. All authors read and approved the manuscript.

ecology↗