terminal mummy wasp

Terminal mummy wasp is a small, slender, parasitic wasp. It occurs in the eastern United States from Maine and Virginia in the east to North Dakota, Colorado, and Oklahoma in the west. It is very common in the east, and may be the most common mummy wasp (genus Aleiodes) in eastern North America.

Adults are orange and black, slender, and 3 ⁄16″ to 5 ⁄16″ (5 to 8 mm) long.

The head is black. There are two large compound eyes at the side of the head and three small simple eyes (ocelli) in a triangle on the top of the head. The distance between each lateral ocellus and the nearest compound eye is about equal to the width of the ocellus. The long, thread-like, antennae have 55 to 62 segments. They are brown in the middle, black at the tip.

The front part of the body (mesosoma) is entirely black. The pronotum is more or less triangular in profile, and extends nearly to the bases of the wings. The first abdominal segment is fused to the thorax and gives the thorax the appearance of having four segments. The small plates covering each wing base (tegula) is yellow.

The remaining part of the abdomen (metasoma) has four segments. The first two segments of the metasoma are orange, the last two black. The third segment is sometimes partially orange. The first segment is narrower at the base than at the tip, and has a longitudinal ridge in the middle. The first three segments are sculptured. On the female, the ovipositor is short, rises in front of the tip of the abdomen, and cannot be withdrawn.

The wings are clear but lightly tinted brown. The thickened leading edge (costal area) of the forewing does not have a cell. In the lower part of the forewing there is only a single recurrent (backward-turning) vein, not two veins forming a cell, as in the ichneumonid wasps. The first cubital cross-vein (1cu-a) crosses after the first medius vein (1M) by more than twice its length. On the hind wing, vein RS is straight, and the m-cu vein is a short stub.

The legs are orange and black. The second part of the leg (trochanter) has two segments. On the hind leg, the fourth segment (tibia) is black with a broad, yellowish-white band near the base. The end part of the leg (tarsus), corresponding to the foot, has five segments. The terminal segment has a pair of claws at the tip. The claws are not toothed. On the hind leg, all segments of the tarsus are black.

Total length: 3 ⁄16″ to 5 ⁄16″ (5 to 8 mm)

Fields

Four to six generations per year: late May to late September

Adults are active at night and are attracted to lights.

The female inserts an egg into the caterpillar of an owlet moth. The larva consumes the living caterpillar, eventually killing it. It completes its development and pupates within the mummified remains of the caterpillar. The appearance of the mummified host is an important feature in identifying the wasp inside. Adults are short-lived. Females live about 32 days, males about 16 days. There are four to six generations per year.

Caterpillars of Noctuidae (owlet moths)

Sources

29, 30, 82, 83.

Several wasps formerly classified in the genus Rogas are now recognized as belonging to the genus Aleiodes. Terminal mummy wasp was formerly classified as Rogas terminalis.