Vespidae

Taxonomy

Vespidae family wasps include the solitary Eumenid wasps and social wasps in the subfamilies Polistinae and Vespinae. Almost all of the Vespidae family wasps in Bee Atlas blocks were Eumenid wasps, which are gentle, solitary wasps that build a small nest in a plant stem or wood tunnel. Eumenids stock their nests with many individuals of some species of leaf-eating arthropod prey (like catterpillars). As such, they can be helpful to gardeners. There are at least 18 species in North America, with Euodynerus foraminatus the most common one in Bee Atlas blocks. Social wasps in the subfamilies Polistinae and Vespinae build large nests with a queen and many workers, and tend to be more aggressive than solitary wasps. A few Polistinae wasp queens used Bee Atlas tunnels as sheltered overwintering places.

Description

Eumenid wasps have a stereotypical “wasp” look to them, but they are solitary and not aggressive like social wasps that are found in the family Vespidae. They are generally black with yellow bands and markings. At rest, their wings fold longitudinally and may appear very thin. They range in size from very small to medium.

Nest Structure

Eumenids are solitary-nesters, with each female building her own nest. They typically use mud or agglutinated sand to build their nest cells and plugs. The plugs frequently have a smooth outer surface, in contrast to the bee Osmia lignaria that also uses mud, but tends to have chunkier, rougher looking nest plugs. Eumenids stock their nests with paralyzed prey, as is typical of solitary nesting wasps. Prey choices include caterpillars and beetle and moth larvae, including leaf mining beetles and moths that are often garden or crop pests.

Hole Sizes

No information at this time.

Voltinism

Possibly multivoltine. Eumenids can have 2 generations per year in Minnesota.

Activity Period

Early summer into early fall.

References

Buck, Matthias. 2008. Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region. Canadian Journal of Arthropod Identification. Accessed from http://www.biology.ualberta.ca/bsc/ejournal/bmc_05/bmc_05.html.

Wasp genera in the family Vespidae found in the Bee Atlas blocks: 

Ancistrocerus

Euodynerus

Polistes

Stenodynerus

Symmorphus