Notes on the biology ofOdynerus dilectus [Hym.: Eumenidae], a predator of the alfalfa weevil,Hypera postica [Col.: Curculionidae]

We describe the nest construction and architecture, and the prey collection and storage behavior ofOdynerus dilectusSaussure, a ground-nesting eumenid wasp of North America that exclusively utilizes weevil larvae of the genusHypera as prey. This species may have potential as a biological control agent of alfalfa and clover weevils in the genusHypera because of its rapid collection of weevil larvae, its gregarious nesting habit, and the apparent ease with which individuals can be transplanted. Other European congeners have many similar characteristics. The potential for adverse interactions betweenO. dilectus andBathyplectes curculionis (Thomson), a parasite ofHypera, is discussed.