ABSTRACTHabitat connectivity and maintaining gene flow between populations is central for long‐term population persistence and is an essential element in conservation planning. However, data on dispersal ability and genetic population structure is lacking for almost all insect species. We here investigate if forest localities in the temperate, central European Black Forest are connected by gene flow. For this, we used partial genome sequencing on specimens of the solitary cavity‐nesting wasp Deuteragenia subintermedia (Hymenoptera, Pompilidae), a forest specialist that primarily nests in deadwood. We assumed that spatially uneven availability of standing deadwood has led to genetic substructuring. Contrary to our expectations, we did not find signs of population structure either on a regional or an individual level. Hence, for this solitary wasp species, dispersal seems not to be restricted across the Black Forest study sites (approximately 90 km distance) and none of the investigated environmental variables impacted genetic connectivity.