helmeted squash bug

Helmeted squash bug is a common, medium-sized, leaf-footed bug. It occurs in the United States east of the Great Plains and in southern Ontario Canada. Adults are found from late May to early July and from early mid-August through October. Their absence in mid-summer suggests that overwintered adults die off before the new generation reaches maturity. Both adults and nymphs feed on a variety of plants.

Adults are dull brown or reddish-brown, elongated oval, ⅝″ (15 to 17 mm) long, and 3⁄16″ to ¼″ (5.0 to 6.5 mm) wide. The body is flattened above and convex below when viewed from the side.

The head is short, squarish, and wider than long. The front of the head is divided into a central lobe (tylus) and two lateral lobes (juga). It does not extend forward between the antennae bases. There are two large, widely spaced, compound eyes on the sides of the head and two small simple eyes (ocelli) on the top of the head between them. There is a distinct raised bump (tubercle) behind each compound eye. The antennae are borne on prominent projections (tubercles) on the upper part of the cheeks (gena). The space between the tubercles is vacant. Each tubercle has a small blunt spine on the outer side. The antennae have four segments. Segments 1 through 3 are dull yellow or reddish-brown. Segment 1 is slightly swollen and twice as long as the head. Segment 4 is darker, bristly, and spindle-shaped, tapered at both ends. The mouth parts are optimized for piercing and sucking, and take the form of a thick, curved, 4-segmented beak (rostrum). The rostrum fits into a groove on the underside (sternum) when not in use. It is stout and short, longer than the head but just reaching the bases of the middle pair of legs.

The thorax is twice as wide as long. The exoskeletal plate covering the thorax (pronotum) is coarsely and irregularly pitted. The lateral margins have 5 to 10 small, blunt teeth. The front corners (humeral angles) jut outward forming a large, rounded tooth. There is no spine at the tip. The upper surface is finely and unevenly pitted. On the male there is a conspicuous cream-colored flap on each side at the rear corner of the thorax.

There are two pairs of wings, and they are held flat over the body when at rest. Between the wing bases there is a large plate (scutellum). The scutellum is broadly triangular, whitish at the very tip, and crossed by fine longitudinal wrinkles.

The forewings (hemelytra) are as long as the abdomen but do not completely cover the sides of the abdomen. The sides of the abdomen are extended, flattened, and exposed (connexivum). The connexivum is conspicuously striped with brown and whitish or yellowish. On the female the connexivum on each side is slightly prolonged at the rear tip, appearing as a pair of teeth at the end of the abdomen. The hemelytra have a thickened, leathery section at the base and a thin membranous section at the tip with a clear dividing line between the two. The membrane is dark brown. Some of the veins in the membrane are forked, some fork and rejoin, network-like (anastomosing).

The third segment (femur) of each leg has spines on the underside. On the male The femurs on the hind legs is moderately swollen, curved, and bumpy (tuberculate) on the upper side. On both sexes the fourth segment (tibia) of all legs is yellowish and straight. On the front and middle legs, they are spotted with dark brown. On the hind legs they are unspotted. The last part of each leg (tarsus), corresponding to the foot, has three segments.

Nymphs are very spiny, and the third antennal segment is dilated.

Total length: ⅝″ (15 to 17 mm)

Width: 3⁄16″ to ¼″ (5.0 to 6.5 mm)

One generation per year: Late May to early October.

When disturbed, adults will either fly away quickly or drop to the ground and remain motionless, feigning death.

Adults overwinter.

Sources

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

Common

Helmeted Squash Bug Nymph (Coreidae: Euthochtha galeator) on Leaf
Carl Barrentine

HELMETED SQUASH BUG Euthochtha galeator
Rob Curtis

Mike Poeppe
6/22/2025

Location: near Houston, MN

Location: Barnes Prairie Remnant, Racine Co., WI

Euthochtha galeator (helmeted squash bug) at Barnes Prairie Remnant, Racine Co., WI, photographed on June 28, 2021. On low-growing shrub.

Location: Woodbury, MN