leaf-footed bug

Widespread and frequently encountered

One generation per year: early June to late September

Open woods, woodland borders and paths, thickets, and roadsides.

This is a 11 ⁄16″ to ⅞″ long, terrestrial, widespread and frequently encountered true bug. It is a relatively large bug (order Hemiptera) but a small leaf-footed bug (genus Acanthocephala), the smallest in North America north of Mexico.

The body is fairly hard and reddish-brown to nearly black. The front (anterior) thoracic shield (pronotum) is covered with short, gold-colored hairs and with small bumps (tubercles).

There are two pairs of wings. They are held flat over the body when at rest. They are longer than the body but do not completely cover the sides of the body.

There are two pairs of wings, and they are held flat over the body when at rest. The forewings (hemelytra) on the mature adult are longer than the abdomen but do not completely cover the sides of the abdomen. 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 triangular section (scutellum) at the base; a narrow area (clavus) behind the scutellum when the wings are closed; and the remaining, broad, marginal area (corium). The hindwings are thin, membranous, and concealed under the forewings.

The head is small, much narrower and somewhat shorter than the pronotum. There is a pair of large compound eyes and a pair of small simple eyes (occelli). The mouth parts are optimized for piercing and sucking. They take the form of a long, 4-segmented beak. The beak projects in front of the head and extends along the underside of the body between the legs. It consists of 4 hair-like blades (stylets) with sharp tips enclosed in a 4-segmented sheath. There are two channels in the beak, one spitting out saliva to keep the food flowing, and one for sucking in liquid food. The two lower jaw-like structures (maxillae) and two lower lips do not have feeler-like structures (palpi) attached. The antennae are exposed, conspicuous, and long, much longer than the head. They have four segments, the basal three dark reddish-brown, the terminal segment bright yellowish-orange.

The third segment (femur) of the hind leg is is stout and either parallel-sided or only slightly expanded toward the end (apex). The fourth segment (tibia) is greatly dilated and scalloped in the basal half, gradually narrowing beyond the middle toward apex, and not at all dilated in the final third. The female tibia is less dilated than the male tibia. The feet (tarsi) have only 3 segments. The tarsi on all legs and the femurs on the front and middle legs are frequently orange or orangish.

Sap from petioles and stems of common ninebark (Physocarpus opulifolius), staghorn sumac (Rhus typhina), and wild grape (Vitis riparia).

Plant sap. Adults have been observed on bird droppings but it is not known if they feed on the droppings.

Bright whitish eggs are deposited singly from mid-June to mid-July. The eggs hatch in 7 to 14 days. The young (nymphs) pass through 5 instar stages in 5 to 10 weeks (mean time 58 days) before becoming an adult. The mean number of days spent as the first through fifth instars is 4, 13, 13, 10, and 19, respectively. Adults overwinter.

They are easily disturbed and are rapid fliers. When handled they squirt a foul-smelling chemical from glands on the sides of their bodies that is an effective deterrent.

Immature individuals are usually concealed, either on the underside of a leaf or on the stem of a plant.

Sources: 7, 29.

Taxonomy
There are 25 known species of leaf-footed bugs (genus Acanthocephala) worldwide, 5 of which occur in North America north of Mexico. Among these, Acanthocephala terminalis has by far the widest distribution and is the only one found in Minnesota.