Diapause in the Colorado potato beetle is characterized by sex-specific gene expression

To survive winter, many insects enter diapause, a hormonally controlled dormancy characterized by metabolic suppression and increased stress tolerance. While these core diapause phenotypes are generally conserved across taxa, sex-specific regulation remains poorly understood. In this study, we characterized the sex-specific transcriptomic profiles of diapausing and non-diapausing adult Colorado potato beetles (Leptinotarsa decemlineata) using RNA-seq. We identified 10,060 differentially expressed transcripts early in the diapause maintenance phase. Among these differentially expressed transcripts, 2,366 were shared between sexes, 4,653 were female-specific, 2,813 were male-specific, and 228 had significant sex*diapause interactions. The shared differential expression profiles support suppression of aerobic metabolism and priming of stress tolerance mechanisms. Beyond these core responses, diapausing females modified cellular maintenance strategies through spliceosome and lipid mobilization pathways, while males altered protein translation, lipid biosynthesis, and metabolic transport systems. Transcripts with sex*diapause interactions support sex-specific modulation of key regulatory pathways like Hippo and TGF-β signaling. We conclude that diapause involves both a core set of sex-independent processes as well as robust, sex-specific regulatory mechanisms.