The Chrysididae are a family wasps with bright metallic coloured bodies. As a result are commonly called jewel wasps, or ruby-tailed wasps. This is a large family consisting of over 3000 species of which there are some 31 species in the UK. Although they have a sting it is non functional and most of the species lack poison. The females are wingless and ant-like in appearance.
These wasps are generally cleptoparasites, laying their eggs in host nests, where their larvae consume the host egg or larva while it is still young. As such the other common name for this family is 'Cuckoo Wasps'.