false terminal mummy wasp

False terminal mummy wasp is a small, slender, parasitic wasp. It occurs in the eastern United States from Maine to Virginia, west to Minnesota and Tennessee. It also occurs in southern Canada from Nova Scotia to Manitoba. The larvae are parasites on caterpillars of lost sallow. Lost sallow is uncommon throughout its range, and so is false terminal mummy wasp.

Adults are orange and black, slender, and ¼″ to 5 ⁄16″ (7 to 8 mm) long.

The head is black. There is a narrow rim or microscopic ridge (occipital carina) that borders the back side of the head. 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 antennae are long, thread-like, and brown. They have 56 to 59 segments.

The front part of the body (mesosoma) is entirely black. The pronotum is saddle shaped, consisting of two large, almost triangular, lateral parts, connected to each other above (dorsally) by a collar-like median band. The band is narrow in the middle, narrower than the distance between the occipital carina and the lateral ocellus. It is long on the sides, extending nearly to the bases of the wings. The first abdominal segment (propodeum) is fused to the thorax giving the thorax the appearance of having four segments. The small plates covering each wing base (tegulae) is yellow.

The remaining part of the abdomen (metasoma) has four segments (tergites). Tergite 1 is orange or red. It is narrow at the front and wider at the rear, not parallel sided. The remaining tergites are entirely black. On the female, the ovipositor rises in front of the tip of the abdomen, and it cannot be withdrawn. It is short, two thirds to almost equal to the length of the first segment of the tarsus (basitarsus).

The wings are transparent and lightly tinted brown. On the forewing, the thickened leading edge (costal area) of the wing does not have a cell. In the lower part of the wing 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 marginal cell is narrowest at the base and widens toward the tip.

The legs are black. The second segment of each leg (trochanter) has two segments. The third segment (femur) on the front and middle legs are black just at the tip. On the hind leg, the fourth segment (tibia) is black with a broad, yellowish-white band near the base. It does not have a comb-like row of flattened hairs (setae) on the inner margin. All of the setae on the tibia are normal and hair-like. The last part of each leg (tarsus), corresponding to the foot, is brown, and it has five segments. The terminal segment has a pair of claws at the tip. The claws are not toothed.

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

Terminal mummy wasp (Aleiodes terminalis) is very similar. The second segment of the rear part of the body is red, not black.

Caterpillars of lost sallow (Eupsilia devia)

Sources

24, 29, 30, 82.

Uncommon

Alfredo Colon
7/31/2018

Location: Woodbury, Minnesota