Ancistrocerus spinolae (Eumenid solitary wasp)
This species of wasp is in the family Vespidae, in the sub family Eumeninae. Eumenids are solitary nest building wasps that 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 many species in North America. Ancistrocerus spinolae may also be a new record for MN. This is typically a more eastern species.
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. Ancistrocerus spinolae is a medium sized black wasp with yellow bands and markings and dusky wings.
Eumenids are solitary-nesters, each female builds her own nests.
They typically use mud or agglutinated sand to build their nest cells and plugs. Frequently plugs have a smooth outer surface. This is 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, beetle and moth larvae, including leaf mining beetles and moths and garden or crop pests.
Ancistrocerus spinolae is known to nest in borings in wood and old mud dauber wasp nests. Partitions an plugs made from agglutinated sand. Prey include caterpillars (Buck et al 2008, Krombein ’67, ’79)
Ancistrocerus spinolae nest in column 1 (3/8 - 7/16") and column 2 (1/4 - 5/16") holes in Bee Atlas blocks.
Possibly multivoltine. Eumenids can have 2 generations per year in Minnesota.
Early summer into early fall.
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.
Minnesota Record Map
These data are from the Minnesota Bee Atlas project.
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