Body length 10-18 mm. Gast comes from the Greek “gaster” meaning stomach, and eruption is self explanatory. Jaculator comes from the Latin meaning a Roman javelin thrower. All appears to explain the long and thin, needle-like ovipositor of the female. The head and thorax are black, and the abdomen is black with a broad orangey copper-coloured band which widens towards the tip. The black femurs are thick at the ends an are like clubs.
As a parasitoid wasp, the females use their long, white-tipped ovipositors to deposit eggs in the nests of various solitary bees, and on hatching the resulting larvae will feed on the grubs of the host as well as on any stored food.
The adult is seen May to September in gardens and meadows. Widespread in England, scarcer elsewhere. Native.
Class Insecta (Insects)
Order Hymenoptera (Ants, Bees, Wasps & Sawflies)
Family Gasteruptiidae (Gasteruptiid Wasps)
Species Gasteruption jaculator (Linnaeus, 1758)
Photos: Female on shed wall, back garden, South Staffordshire 26th May 2020 © Peter Hillman