The aim of this project is to perform population genomic and transcriptomic analyses using sequencing data from the common bluetail damselfly (Ischnura elegans), a polymorphic insect species that has been studied in the lab by E. Svensson for two decades. This species has a female-limited genetic colour polymorphism that is maintained by negative frequency-dependnet selection caused by male mating harassment. The genomic research we will carry out here will focus on several different questions related to this colour polymorphism, namely 1/the genomic basis of the polymorphism, 2/consequences for gene expression, 3/links to thermal adaptation, 4/role in sexual antagonism and 5/biogeographic consequences. We will use data from Swedish and European populations and experimental data from mesocosm experiments carried out in southern Sweden at Stensoffa Ecological Field Station (Lund University) for this purpose. I am a full professor at the Department of Biology (Lund University) since 2008, and my research on the genetics and population biology of I. elegans has been funded by the Swedish Research Council (VR) since the year 2000, when my long-term studies were initiated.