Species diversity in the Strepsiptera parasite genus Stylops, parasitizing solitary bees of the genus Andrena, has been vastly underestimated in the past. In this project we will use whole genome sequencing data (shotgun Illumina) to reconstruct the phylogeny of this Holarctic genus and test the species limits in relation to host species. Both fresh and museum specimens is used to have as wide a host spectrum as possible as well as maximizing the geographical spread of samples. This is a PhD project that has come half-way (Licentiate done May-23) with 1.5 years left to go. In a sister project, a reference-quality genome of one species, Stylops ater, has been produced within the Swedish node of ERGA (European Reference Genome Atlas) in collaboration with NBIS and SciLifeLab, which will aid assembly and the extraction of an orthologous gene dataset for analysis. This was based on HiFi PacBio long read technology, with NBIS responsible for the assembly, annotation and curation.