damsel bug

Damsel bugs prey on aphids, caterpillars, and other insect nymphs and eggs, including many agricultural pests. They are considered beneficial, though they are not available commercially. Nabis roseipennis is a small, predatory, damsel bug. It is considered beneficial because it preys on many agricultural pests. It occurs across North America and southern Canada, but it is most common from the northeast to the Midwest.

Adults are soft-bodied, elongated, about ¼″ long, slender, less than ⅛″ wide, and cone-shaped. They are tan and mottled with shades of reddish-brown and gray.

The head is small, cone-shaped, and much narrower than the thorax. At the front of the head there is a rounded lobe (tylus) that projects forward. The tylus is dark along the sides. The neck is very short. There are two large compound eyes and two small simple eyes (ocelli). The compound eyes are bulging. At the top of the head there are two converging pale lines with a dark, hairy, V-shaped area between them. The occeli are large and positioned at the back (posterior) ends of the pale lines. The antennae are exposed, conspicuous, and long, much longer than the head but not quite as long as the body. They have four segments. The first segment (scape) is shorter or as long as the width of the head through the eyes. The end of the second segment is dark. The fourth segment is longer than the scape. The mouth parts are optimized for piercing and sucking. They take the form of a long, prominent, 4-segmented beak that extends along the underside of the body between the legs when not used. The beak is slender and much longer than the head.

The abdomen is much wider than the thorax.

There are two pairs of wings, and they are held flat over the body when at rest. The small triangular plate between the wing bases (scutellum) may have depressed, semicircular spots on each basal angle, but if present they are poorly developed, not conspicuous. Most adults have long, fully developed wings. Some have wings that extend beyond the middle of the abdomen but do not completely cover it. When fully developed, the forewings (hemelytra) on the mature adult are longer than the body and completely cover the sides of the body. They have a thickened section at the base and a thin membranous section at the tip with a clear dividing line between the two. The thickened basal part is comprised of a narrow area (clavus) behind the scutellum when the wings are closed, and the remaining, broad, marginal area (corium). At the end of the corium there is a small but distinct triangular area (cuneus). There is one unbranched vein through the clavus, and two long veins in the corium, one of them split in the middle forming a diamond-shaped cell. A long submarginal vein in the membranous section separates an inner row of long closed cells and an outer (marginal) row of short open cells. The hindwings are thin, membranous, and concealed under the forewings.

The legs are long and yellowish-tan. The third segment (femur) and fourth segment (tibia) of each leg is heavily spotted above. The femurs on all legs have heavy dark spotting above. On the front leg they are thickened. On the front and middle legs they have a row of small, stiff bristles below. The tibia on all legs are also heavily spotted above. On the front legs they have double row of black teeth along the inner edge. On the middle legs they have a double row of black spines. The end part of the leg (tarsus), corresponding to the foot, has only 3 segments. The tip of each segment is dark.

Total length: about ¼″

Grassy fields, gardens, agricultural fields

One generation, early May to early October

Adults are usually found on grass or low on vegetation.

Adults females probably overwinter after mating and deposit eggs in the spring. Nymphs pass through five stages (instars) before emerging as adults.

Small insects, insect nymphs, and insect eggs, including aphids, mites, and caterpillars.

Sources

24, 27, 29, 30, 82, 83.

Widespread in North America. Common in Minnesota.

Location: Albany, NY

Location: Woodbury, Minnesota