Rapid evolution of insecticide resistance in the Colorado potato beetle, Leptinotarsa decemlineata

Despite considerable research, efforts to manage insecticide resistance continue to fail. The Colorado potato beetle (CPB), Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), epitomizes this problem, as it has repeatedly and rapidly evolved resistance to>50 insecticides. The patterns of resistance evolution are intriguing, as they defy models where resistance evolves from rare mutations. Here, we synthesize recent research on insecticide resistance in CPB showing that polygenic resistance drawn from standing genetic diversity explains genomic patterns of insecticide resistance evolution. However, rapid gene regulatory evolution suggests that other mechanisms might also facilitate adaptive change. We explore the hypothesis that sublethal stress from insecticide exposure could alter heritable epigenetic modifications, and discuss the range of experimental approaches needed to fully understand insecticide resistance evolution in this super pest.