tapered mason wasp

not listed

not listed

not listed

Tapered mason wasp is a solitary potter or mason wasp. It occurs in North America east of the Great Plains. It occurs in the southeast quarter of Minnesota, where it reaches the northwest corner of its range, but is absent from the remainder of the state.

Adults are small to medium-sized and black with yellow markings. The front part of the body (mesosoma) is connected to the rear part (metasoma) by a narrow waist (petiole). The entire body is distinctly pitted (punctate).

The female has a 7⁄16″ to ⅝″ (11.0 to 15.5 mm) forewing length.

The head is black. There are two large compound eyes, one on each side of the head, and three small simple eyes (ocelli) in a triangular pattern at the top of the head between the compound eyes. The inner margin of each compound eye is notched. The antennae are thread-like and have 12 segments, including a long first segment (scape) at the base, a short second segment (pedicel), and a whip-like section (flagellum) with 10 segments (flagellomeres). The scape is rust-colored or yellowish above, yellow below. The pedicel is rust-colored or yellowish. The flagellum is entirely black above, rust-colored or yellowish below, especially near the base, becoming black at the tip. The last flagellomere is flat, not hooked at the tip. The jaws (mandibles) are brownish-black, long, and knife-like. The plate on the face (clypeus) is black. There is a small yellow spot (postocular spot) behind each compound eye.

The thorax is black and has three segments, the prothorax, mesothorax, and metathorax. However, the first segment of the abdomen (propodeum) is fused to the thorax, giving the thorax the appearance of having four segments. The upper plate on the prothorax (pronotum) is short and collar-like. It extends rearward on the sides to the plate at the base of each wing (tegula). It appears horseshoe-shaped when viewed from above, triangular when viewed from the side. It is mostly black except for a yellow band on the front margin of the upper (dorsal) surface. The band is widest at the sides, narrowing to the middle, and is sometimes narrowly interrupted in the middle. There is sometimes a small yellow spot near the wing bases. The thorax is otherwise usually entirely black, though there is sometimes a pair of small yellow spots on the sides. The plate covering the middle segment of the thorax (mesoscutum or scutum) has a small projection at each rear corner. The first abdominal segment forms a short petiole that connects the abdomen to the thorax.

The first segment of the metasoma is somewhat narrowed but not petiole-like. It is black with a yellow band at the rear. The band is widest in the middle and has a narrow notch in the middle. The remaining segments are entirely black. The second segment is larger than the remaining segments combined.

The wings are dark and have purplish reflections. They are folded longitudinally over the body when at rest. On the forewing, the first discoidal cell is very long, about half the total length of the wing. There are three submarginal cells.

The legs are mostly yellow except for the third segment (femur) of each leg, which is black. The first segment (trochanter) is not divided – it has just one segment. The fourth segment (tibia) of the middle leg has a single spur at the tip. The last part of each leg (tarsus), corresponding to the foot, has five segments.

The male is smaller. It has a 5⁄16″ to 7⁄16″ (8.0 to 11.5 mm) forewing length. The plate on the face (clypeus) is yellow and there is a yellow spot between the antennae bases. The antennae have 13 segments. The second and third metasomal segments have a yellow band on the rear margin.

Female forewing length: 7⁄16″ to ⅝″ (11.0 to 15.5 mm)

Male forewing length: 5⁄16″ to 7⁄16″(8.0 to 11.5 mm)

The female makes a nest in preexisting holes.

Sources

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

Three subspecies have been described. One subspecies was later raised to species status and another was synonymized with it. There are no subspecies currently recognized.

Potter Wasp

I photographed this wasp in my backyard in La Crescent yesterday on a Wild Bergamot blossom.

Location: La Crescent, MN

I photographed this wasp in my backyard in La Crescent yesterday on a Wild Bergamot blossom.