Regional differences in gene regulation may underlie patterns of sensitivity to novel insecticides in Leptinotarsa decemlineata

Agricultural insect pests frequently exhibit geographic variation in levels of insecticide resistance, which are often presumed to be due to the intensity of insecticide use for pest management. However, regional differences in the evolution of resistance to novel insecticides suggests that other factors are influencing rates of adaptation. Comparisons of gene expression between northwestern and eastern U.S. populations revealed constitutively elevated expression of an array of detoxification genes in the East, but no evidence of additional induction when exposed to imidacloprid.