The cuckoo bee. Shiny, metallic blue or green, with a detailed surface all over their body. They usually don’t sting, and are a type of parasitic wasp. Their larvae are ectoparasites (external parasites) of other bee and wasp larvae. The name “cuckoo wasp” comes from the fact that this insect, like the cuckoo bird, lays her eggs in the nest of an unsuspecting host.