ichneumonid wasp

not listed

not listed

not listed

Colpotrochia trifasciata is a small, black and yellow, ichneumonid wasp. It occurs in the United States from Maine to Georgia, west to Minnesota and Missouri, and in Canada from Nova Scotia to southern Ontario. It is found in shade on shrubs.

The head is black. The antennae are very long. They are yellow on the underside, brownish-yellow on the upper side. The basal segment (scape) is always entirely yellow.

The thorax is black. There is a squarish yellow blotch on the propodeum and beyond it a horizontal stripe of the same width. Two small plates (tegulae), one covering each wing base, are yellow.

The abdomen is long, slender, and black. There is a broad yellow band at the rear of segments 1, 2, and 3, and sometimes a narrower partial band on segment 4.

The wings are clear. The forewing is ¼″ to 5⁄16″ (6.0 to 7.5 mm) long. It does not have a second submarginal cell (areolet). On the hindwing, the outer cross vein of the medial cell (nervellus) is vertical and is broken a little below the middle.

The legs are mostly yellow. On the hind legs the third segment (femur) is mostly black, and the fourth segment (tibia) is black just at the tip.

Forewing length: ¼″ to 5⁄16″ (6.0 to 7.5 mm)

June to September

Sources

24, 27, 29, 30, 82, 83.

Jay Bancroft
10/17/2024

Location: Newark Delaware

Location: Woodbury, MN