show Abstracthide AbstractWinter diapause consists of cessation of development that allows species to survive unfavourable conditions. Although in some insect species winter diapause is obligatory, in others it has also been shown to be facultative. As winter diapause may bear various costs, questions have been raised about the evolutionary mechanisms maintaining facultative diapause. Here, we explored to what extent a facultative winter diapause affects the transcriptome in the damselfly Ischnura elegans, and whether these effects were latitude-specific.