(1st Place) Metabolic component of diamide insecticide resistance in Georgia populations of diamondback moth, Plutella xylostella

The diamondback moth (DBM), Plutella xylostella, is a globally distributed, specialist pest of cruciferous crops. Recent studies have monitored the increasing levels of insecticide resistance in DBM populations around the world. In the Southeastern U.S., special interest has been placed on the diamide insecticides (IRAC Class 28) which target the ryanodine receptor (RyR). Our lab previously identified several well-characterized target site mutations of the DBM RyR (G4946E, I4790M, and I4790K) in Georgia and Florida populations. Each of these mutations have been linked to high levels of diamide insecticide resistance in DBM populations in Asia, providing a potential explanation for the reduced efficacy in the area. However, we are also interested in monitoring populations for metabolic resistance to these insecticides. Members of several gene families, such as cytochrome P450’s and UDP-glucuronosyltransferases, have been identified and linked to chlorantraniliprole resistance via over-expression upon exposure to sublethal doses of the insecticide. Here, we present data from several populations that were exposed for 24 hours to sublethal doses of chlorantraniliprole and methomyl. Quantitative Polymerase Chain Reaction (qPCR) was then used to determine differences in expression of genes of interest in treated and untreated groups.