Specimens of Onychiurus procampatus (Collembola) observed grazing on fungal mycelia were collected from the surface soil of three differently manged upland grasslands. A general trend of an increasing proportion of Collembola with a full gut was found along a gradient of reduced sheep management intensity, which was correlated with increased fungal biomass. In the laboratory, this collembolan showed a consistent order of preference for the mycelium of seven common fungal species isolated from the field sites.