crabonid wasp

not listed

not listed

not listed

Alysson oppositus is a species of crabonid wasp. It occurs in the United States and southern Canada. In the U.S. there are relatively few records of this species, but those records are mostly from New Hampshire to Virginia, west to Minnesota and Iowa, with just single records in Georgia, Tennessee, and Colorado.

Adults are small, about 5⁄16″ (8 mm) in length. The body is long and slender.

On the female the head is mostly black. The mouth and the inner orbits of the compound eyes are yellow. The plate on the face (clypeus) is mostly broad but narrowed below, with three teeth at the lower margin. The jaws (mandibles) each have a small tooth just before the tip.

The antennae are mostly black and have 13 segments, consisting of a long basal segment (scape), a small connecting segment (pedicel), and a whip-like section (flagellum) with 11 segments (flagellomeres). The scape is black above, yellow below.

The thorax is black. There is a small yellow spot in front of each wing base. A small plate (tegula) covers the base of each forewing. The plate on the first thoracic segment (pronotum) is short and collar-like. It has a small, rounded lobe on each side that does not quite reach the tegula. The plate on the middle segment of the thorax (mesonotum) is expanded on each side into a thin plate (lamina) that extends over the base of the tegula. The rear face of the thorax, when viewed from behind, has two teeth on each side.

The rear part of the body (metasoma) is slender, shiny, and mostly black. The first segment (tergite) of the metasoma is red. The second tergite is red on the front half, with a large, rounded, bright yellow spot on each side, and black on the rear half.

The wings are slightly tinted brown and have dark veins. The forewing is tinted a little darker toward the tip. The cell (stigma) on the leading edge (costal margin) of the forewing is large and brown. There are three submarginal cells. The second and third submarginal cells are small. The second submarginal cell is petiolate. The lobe at the base of the hindwing (jugal lobe) is small but it is much larger than the tegula.

The legs are mostly black and have very short spines. On the middle legs the fourth segment (tibia) has just a single spur at the tip. The last part of each leg (tarsus), corresponding to the foot, is yellow.

The male is similar to the female. The metasoma is entirely black except for the two yellow spots on the second tergite. The antennae have only 10 flagellomeres. The last flagellomere is as long as the first and is curved inward. The wings are not distinctly tinted except in a few cells.

Nests are grouped together (gregarious), often in sandy areas. The female excavates a short, slanted burrow with one to five cells. Each cell has a single egg and is provisioned with one to twelve adult or larval leafhoppers.

Leafhoppers

Sources

24, 29, 30, 82, 83.

This species has no common name. One of the common names for the family Crabronidae is crabonid wasps, and it is adopted here for convenience.

Location: Woodbury, MN