What is wasp-like, shiny black, two inches long, and very slender? The answer is a pelecinid (pel-ah-SIN-id) wasp. You can recognize this insect by its large size and conspicuously long abdomen. This wasp belongs to the family Pelecinidae of which there is just one species present in North American, Pelecinus polyturator. Virtually every pelecinid wasp you see is a female. Males, about half the size of females, are rare and usually not seen.
Adult wasps emerge from mid to late summer. This wasp is a parasite of the white grubs of June beetles. It uses its long abdomen to probe into the soil until it reaches larvae to lay its eggs. However, finding a pelecinind wasp in your yard does not necessarily mean you have grubs in your own yard. It is most likely just incidental as they can fly in from nearby areas.
Despite its impressive abdomen, a pelecinid wasp does not have a stinger. If captured it can use its abdomen to jab at its captor to protect itself although it would rarely be able to break human skin. Pelecinid wasps are unaggressive towards people and for all intents and purposes are harmless to us. If you see one just ignore and let it go on its way.
Published in Yard and Garden Line News, September 15, 2003