Evolution of feeding behavior and gustatory receptors in bombycoid moths

New advancements in whole-genome sequencing have allowed researchers to study the correlations between the evolution of different insect traits. The functionality of adult mouthparts within the superfamily Bombycoidea (~4700 species) shows significant variation, as some species have extraordinarily long proboscides (e.g., Darwin’s hawkmoth), and others have mouthparts which have been greatly reduced, or entirely lost. Non-functional proboscides have been observed in many species of Saturniidae and Bombycidae, but are also thought to occur in some hawkmoths (Sphingidae). We performed an ancestral state reconstruction of adult feeding behavior on a phylogeny of Bombycoidea to examine the evolutionary history of feeding gains and losses. Our results set the groundwork to compare feeding behavior with gene presence. We hypothesize that signatures of evolution in sugar gustatory receptor genes are correlated with gains and losses in adult Bombycoid feeding. Species that have lost the ability to feed as adults may show relaxed selection on adult sugar receptor genes. We use genetic and receptor data from existing Lepidoptera genomes to test these hypotheses.