Exploring the connections between digestion and detoxification in microevolution of insecticide resistance of the tea tortrix moth, Adoxophyes honmai

In comparing two populations of tea tortrix moth, Adoxophyes honmai, we found the absence of a cost of resistance. We conducted an RNA-seq experiment comparing the midgut tissue in these two populations, one susceptible and one resistant, to explore and identify midgut-specific differences in gene expression.

We found upregulation in detoxification enzymes commonly associated with insecticide resistance in the midguts of resistant larvae, but also noted differences in digestive enzyme gene expression. This raised the possibility that insecticide resistance coevolved with enhanced digestive capabilities, potentially offsetting putative costs of resistance. Future studies on fitness costs of resistance may do well to consider other physiological systems and their interactions with direct mechanisms of resistance.