short-winged nabis

Short-winged nabis is a small damsel bug. It occurs in the United States in the east from Maine to Virginia, west to Minnesota and Illinois, and in the west in Washington and Oregon. It occurs across southern Canada from Nova Scotia to British Columbia.

Adults are active from April to September. They are found low on vegetation in an array of habitats, including fields and gardens. They feed on soft-bodied insects.

Adults are ¼″ to 5⁄16″ (6.0 to 8.0 mm) in length. The body is soft, slender, and oblong egg-shaped. The coloration is light brown, light yellowish brown, or light reddish brown (pale), with dark mottling. There are two forms: the short-winged (brachypterous) form, and the long-winged (macropterous) form. On the short-winged form, the wings reach beyond the middle of the abdomen. On the long-winged form, the wings extend to the tip of the abdomen. The short-winged form is more common.

The head is small and slender. At the front of the head there is a rounded lobe (tylus) that projects forward. The neck is very short. There are two large compound eyes and two small simple eyes (ocelli). The compound eyes are bulging. Though smaller than the compound eyes, the ocelli are relatively large. Behind the eyes the head is parallel sided or almost parallel sided. 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 as long or only slightly longer than the width of the head through the eyes. The fourth segment is longer than the scape. The mouth parts are optimized for piercing and sucking. They take the form of a prominent, 4-segmented beak. The beak is slender and much longer than the head. It extends along the underside of the body between the legs when not used. The underside of the head is mostly yellowish to brick red.

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

There are two pairs of wings, and they are held flat over the body when at rest. When fully developed, the forewings (hemelytra) on the mature long-winged adult 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). The clavus is widened at the rear. 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.

Each abdominal section is enlarged laterally creating a continuous, flat, border (connexivum). On the underside of the abdomen, the connexiva are separated from the body by a distinct longitudinal groove.

The legs are long and pale. On the front legs, the third segments (femurs) are slightly thickened and are heavily spotted above. The fourth segments (tibiae) are armed with sharp, spine-like teeth. On the middle and hind legs, the femurs are also spotted. The end part of the leg (tarsus), corresponding to the foot, has only 3 segments.

Total length: ¼″ to 5⁄16″ (6.0 to 8.0 mm)

An array of habitats, including fields and gardens

April to September

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.

Soft-bodied insects

Soft-bodied insects

Sources

24, 29, 30, 82.

Alfredo Colon
6/7/2021

Location: Woodbury, MN