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University of Minnesota Extension

Species guide - species detail

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Crabronidae (Nest-building solitary wasps)



The family Crabronidae consists of many species of solitary nesting wasps, some of which were formally classified as Sphecidae. This page is a general description of the family and encompasses all crabronids from our project that were not identified to genus or species.


Crabronid wasps are frequently all dark, with few markings and almost no hair on their bodies. They do not fold their wings at rest. Crabronids often have a square shaped head when seen face-on, have low set antennae and a silvery “mustache” of hairs or yellow markings on their face. Many are quite small. Most of the crabronids in Bee Atlas blocks are small wasps that prey on aphids.

Nest Structure

Crabronids are solitary nesting wasps and stock their nests with paralyzed prey. Many crabronids store aphids in their nests as the food source for their young. They may collect hundreds of aphids per nests. Most crabronids in Bee Atlas blocks use light-colored resin to seal their nests, and may stick debris to the plug surface. Resin plugs with a lot of debris can be confused with mud with a lot of debris.

Hole Sizes

Crabronid wasps are common in the Bee Atlas blocks. They primarily use holes in the 3rd column (the smallest holes) though we do see nests in the upper second column holes.


Univoltine-Multivoltine. They may have multiple generations per year.

Activity Period

Summer into early fall.


No information at this time.

Minnesota Record Map

These data are from the Minnesota Bee Atlas project.

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