Urbanization is affecting arthropod communities worldwide, for example by changing the availability of food resources. However, the strength and direction of a community’s response are species-specific and depend on the species’ trophic level. Here, we investigated interacting species at different trophic levels in nests of cavity-nesting bees and wasps along two urbanization gradients in four German cities using trap nests. We analyzed bee and wasp diversity and their trophic interaction partners by metabarcoding the DNA...