Pennsylvania ambush bug

not listed

not listed

not listed

There are 17 species of jagged ambush bugs (genus Phymata) that occur in North America north of Mexico. Only two species have been recorded in Minnesota.

Pennsylvania ambush bug is a small, well-camouflaged, ambush bug. It occurs in the United States east of and just west of the Mississippi River and in adjacent Canadian Provinces. A disjunct population has been reported in Colorado. It is rare in Minnesota, where it is at the western extent of its range.

Adults are 5 ⁄16″ to ½″ (7.5 to 12 mm) in length and light colored with dark markings. The light color may be yellow, yellowish-white, yellowish-green, greenish-yellow, or any combination of these. The dark markings are usually dark brown to almost black but are sometimes medium brown, brownish-orange, or brownish-yellow. Males tend to be darker than females.

There are two large compound eyes, one on each side of the head, and two simple eyes (ocelli) on the top of the head (vertex). The antennae have four segments. The last segment is only slightly enlarged (clubbed). The collection of protruding mouthparts (beak) is short, has three segments, and is optimized for sucking.

The exoskeletal plate covering the thorax (pronotum) has jagged, spiny, rear corners. This feature gives the genus its common name. The pronotum usually has four alternating bands, two light and two dark. These may be obscure or appear as a pair of light spots on each side. The plate between the bases of the wings (scutellum) is triangular and shorter than the pronotum.

The abdomen has a flattened, greatly enlarged margin (connexivum). It is more or less diamond-shaped, widest in the middle, and a broadly rounded tip (apex). It is pale with a broad dark band across the widest part. The segments of the connexivum are dilated, though this is difficult to see in photos. The widest segment has angular sides with one corner that sticks out farther than the adjacent segments. This makes the overall shape of the connexivum look distinctly notched, not smooth. Connexiva on abdominal segments 3 and 4 usually do not have a dark marginal spot.

The wings at rest are held folded over the back. They cover only the middle portion of the abdomen, leaving the sides exposed.

The legs are pale. On the front legs the third segment (femur) is greatly enlarged, optimized for grasping large prey. When the front legs are folded, the fourth segment (tibia) fits into a groove on the bottom of the femur. The last part of the leg (tarsus), corresponding to the foot, has three segments.

Total length: 5 ⁄16″ to ½″ (7.5 to 12 mm)

Jagged ambush bug (Phymata americana) connexivum is smooth, not notched at the widest part. The segments of the connexivum are not dilated. It is much more common in Minnesota. On abdominal segments 3 and 4, each connexiva usually has a dark marginal spot.

Open and semi-open areas, including forest edges, farms, meadows, and gardens.

Mid-July to late September

Adults prefer yellow or blue flowers where their camouflage is most effective. They may have the ability to change their colors somewhat in response to their environment. They can capture prey up to ten times their own size.

Small insects

Bees, butterflies, flies, day-flying moths, and other true bugs.

Sources

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

Rare in Minnesota

The genus Phymata was formerly placed in its own family, Phymatidae.

Location: Albany, NY

Location: 1 mile west of Houston, MN

Location: just west of Houston, MN