Crabronid wasps

Overview

Crabroninae is a subfamily of wasps known as crabronid wasps. There are about 4,660 species in more than 100 genera in 7 tribes worldwide, about 520 species in 31 genera in 6 tribes in North America north of Mexico, and at least 68 species in Minnesota.

These are solitary, predatory wasps. They are usually found on flowers. The female makes a nest in a hollow stem, an abandoned gallery in wood, or in the ground. She lays her eggs in paralyzed, living prey. Most species prey on flies.

Description

Most species are 5 ⁄16″ to ¾″ long. The thorax and abdomen on most are black with yellowish markings. The upper surface of the first thoracic segment (pronotum) is short and collar-like. The body hairs are unbranched. The head and eyes are large and together are squarish in appearance. The antennae bases are very low on the face. The wing veins extend nearly to the margin. There is only a single submarginal cell on the forewing. The outermost tip (apex) of the marginal cell is squared off. On the hind legs the first of the group of terminal segments (tarsi) is slender.