Five-banded thynnid wasp

Description

Five-banded thynnid wasp is a common, small to medium-sized, parasitic wasp. It occurs in the United States from the East Coast to the Great Plains, and in southern Ontario and Quebec Canada. It is common in Minnesota.

Adults are active from July to September. Little information about the biology of Myzinum quinquecinctum can be found. Adults in the genus Myzinum are found in a wide range of habitats, including meadows, fields, and lawns. They feed on pollen and nectar from the flowers of at least 22 species of plants, mostly sunflowers, daisies, asters, and allies (family Asteraceae) and carrot (family Apiaceae). The larvae are external parasites on the larvae of beetles, mostly scarabs (family Scarabaeidae) and especially May beetles (Phyllophaga spp.), but also tiger beetles (family Cicindelidae).

Females are 7⁄16″ to 11⁄16″ (11 to 18 mm) in length and their bodies are robust. The body is mostly black with yellow areas and markings, and it is somewhat hairy. The front part of the body (mesosoma) is connected to the rear part (metasoma) by a narrow waist.

There are two large compound eyes on the sides of the head and three simple eyes (ocelli) in a triangle on top of the head. The compound eyes are notched to slightly indented on the inner margin. There is a yellow band along the inner and outer eye margins, continuing as a broad, yellow, transverse band passing through the antennae bases. The plate on the face (clypeus) is partially yellow. The jaws (mandibles) are orange. The antennae are smooth and thread-like. They are orange, they have 11 segments, and there is a yellow band along the upper side of the first segment (scape).

The thorax is longer than wide and it has three segments, from front to back the prothorax, mesothorax, and metathorax. However, the first segment of the abdomen (propodeum) is fused to the thorax, giving the thorax the appearance of having four segments. The upper plate on the prothorax (pronotum) is short and collar-like. It extends rearward on the sides to the plate at the base of each wing (tegula). It appears horseshoe-shaped when viewed from above, triangular when viewed from the side. It is mostly black except for a large, yellow, triangular spot on the front margin on each side and a narrow yellow stripe across the rear margin.

On the mesothorax, the large front plate (scutum) has a yellow, broadly U-shaped spot in the middle and a yellow spot on each side. The rear plate on the mesothorax (scutellum) and the plate on the third thoracic segment (metanotum) each have a yellow rectangular spot in the middle. The plate on each side of the second segment (mesopleuron) has a large yellow spot at the front and sometimes a spot at the rear. The tegulae are yellow. On the propodeum, there is a yellow rectangular spot near each lateral margin toward the rear.

The surface of the metasoma is covered with silvery hairs except for the last segment, which is shiny. The upper part (tergum) of the first four segments (terga I–IV) have a broad, complete, yellow band near the rear (subbasal). The underside (sterna) of segments II–VI or V have a lateral yellow spot. The last metasomal segment has two rear lobes.

The wings are evenly tinted orange.

The legs are orange.

Males are 5⁄16″ to ⅝″ (8 to 16 mm) in length and their bodies are slender. The antennae are black, they have 12 segments, and there is a small yellow spot on the upper side of the scape. The clypeus is entirely yellow. The pronotum has a narrow yellow band on the front margin that is interrupted in the middle, and a broad yellow band on the rear margin. The scutum, scutellum, and metapleuron each have a broad yellow spot in the middle. The mesopleuron has a large yellow spot at the front and a small spot at the rear. The metasoma is cylindrical, the yellow bands are narrower, and the last segment has an upwardly curved false stinger. The wings are darkened toward the tip.

Size

Female Total length: 7⁄16″ to 11⁄16″ (11 to 18 mm)

Male Total length: 5⁄16″ to ⅝″ (8 to 16 mm)

Similar Species

Habitat

A wide range of habitats, including meadows, fields, and lawns

Ecology

Season

July to September

Behavior

Life Cycle

Larva Food/Hosts

Larva of beetles, mostly in the families Scarabaeidae and Cicindelidae

Adult Food

Pollen and nectar of mostly Asteraceae and Apiaceae plants.