Black Damsel Bug

Appearance

The body is soft and somewhat ant-like in appearance, and late stage (instar) nymphs are ant mimics. Adults average 10 mm long. The head, thorax, and abdomen are black and shiny.

The head is narrowed into a distinct “neck” behind the eyes. There are two large compound eyes on the side of the head and two small simple eyes (occeli) on top of the head. The antennae are yellowish, thread-like, and long, more than half as long as the body. They have four segments. The basal segment (scape) is not twice as long as the head and is not abruptly thickened. The beak-like projection of the head that contains the piercing mouthparts (rostrum) is slender, yellowish, and has four segments.

The exoskeletal plate covering the thorax (pronotum) has a wide, distinct collar at the end (nearest the head).

The abdomen is in the shape of an elongated oval and is much wider than the thorax. Each abdominal section is enlarged laterally creating a continuous, flat, border (connexivum). The margins of the connexivum are yellowish.

There are two pairs of wings. The forewings (hemelytra) on the mature adult are thickened, very short, and do not have a membranous section. The hindwings are thin, membranous, and concealed under the forewings.

The legs are long, slender, and yellowish. They are not ringed. The third segment (femur) of the front legs is slightly enlarged.

Naming

Nabis (subgenus Nabicula) subcoleoptratus
Nabicula subcoleoptrata

Behavior

Despite their small size, damsel bugs are able to deliver a painful bite when harassed.

Habitat

Moist grassy places

Reproduction

Eggs overwinter. Late instar nymphs are ant mimics.

Food

Adults prey upon plant bug (Miridae) nymphs. Additionaly, adults and nymphs are predators of many different types of insects, including aphids, moth eggs, and small caterpillars, including corn earworm, European corn borer, imported cabbageworm and some armyworms.

Predators

Damsel bugs are attacked by a number of natural enemies, including tachinid flies, wasps and fungi.