ichneumonid wasps

Melanichneumon is a genus of ichneumonid wasp. It occurs in eastern Europe, western Asia, and North America. There are 18 Melanichneumon species in North America north of Mexico, and at least one species in Minnesota.

The head is narrow behind the eyes. The jaws (mandibles) have one large apical tooth and one small subapical tooth. On the female the antennal segments (flagellum) are flattened above, short, considerably widened beyond the middle, and strongly narrowed at the end.

What appears to be the last segment of the thorax is actually the first segment of the abdomen fused to the thorax (propodeum). The superomedial area (areole) of the propodeum in the female is large and shaped like a gothic arch. On males it is shorter, and horseshoe or half-moon shaped.

On most species the last abdominal segment has a white mark above, and on more than half of the species there is also a white mark on each side of the last segment near the tip.

It is difficult to identify a North American Melanichneumon to the species level. The eighteen (or nineteen) species are very similar structurally, and the coloration of a single species may differ from region to region. Taxonomically it is one of the two most difficult groups of Ichneumonidae.

Sources

24, 27, 29, 30, 82.

Location: Woodbury, Minnesota