Digger Wasp
(Common Name)
Parasitoid
(General Category)
Hymenoptera: Scoliidae
(Taxonomic Classification)
Scolia dubia
(Scientific Name)

Digger wasp adult with rollover ID charactersGreen June Beetle Adult and Larva (Grub)

Description: These are large, hairy, dark-colored wasps with dark wings and characterisitc bright colors on the ends of their abdomens. They are parasitoids of lawn root-feeding grubs such as Green June Beetles. Digger wasps are often seen feeding on flower nectar, as well as flying over lawns searching for mates. If lawns have large numbers of grubs feeding on the roots, there may be large numbers of digger wasps. Once they locate a grub, they will dig down in the soil to find it, paralyze it with a sting, then make a small chamber and lay an egg on the grub. The egg hatches into a grub-like larva that feeds on the beetle grub like a leech until it finally consumes so much of the host that it kills it. These wasps are solitary, so after mating females hunt for and paralyze grubs on their own. Although these wasps look scary, they are harmless unless grabbed and forced to sting in self defense.

Identification:  Rollover or tap pictures for tips on how to identify these parasitoids. Adults: Very dark body and hairy bodies. The end of the abdomens are rust red with two yellow spots. The wings are not folded up accordion-style at rest as they are in paper wasps. The ends of the wings have many fine folds or wrinkles. Video of digger wasp. Larvae: Because the grub-like larvae develop by feeding on paralyzed beetle grubs underground, they cannot be seen unless a grub is purposely dug up.

Value in Pest Management:  Digger wasps can contribute significantly to natural control of lawn grub populations, and are therefore a valuable presence in urban areas. They are not sold commercially.

Origin and Distribution:  Native, throughout the United States (http://www.discoverlife.org/mp/20q?search=Scolia+dubia).

For More Information:  (LINKS)

http://www.ces.ncsu.edu/depts/ent/notes/O&T/lawn/note12/note12.html