common sawfly

Macrophya trisyllaba is a black, small to medium-sized, common sawfly.

The female averages ⅜″ (10 mm) in length. The head is black with white mouthparts and often a pair of white spots on the back of the head. The antennae have 9 segments. They are thread-like, entirely black at the base, and entirely white on segments 5 to 9 or 6 to 9. Rarely, they are all black.

The plate covering the thorax (pronotum) is black with white markings. There is a white spot on each side of the forward (dorsal) edge of the pronotum. The two spots are sometimes narrowly connected. There is also a pair of spots in the middle of the pronotum that usually merge into a single V-shaped spot. These spots may be bold and conspicuous, small and partially developed, or even absent. The triangular plate between the wing bases (scutellum) is partly or entirely white.

The thorax and abdomen are broadly connected. The abdomen is usually entirely black, sometimes with the forward edge of some or all of the segments white.

The fourth segment (tibia) of the front leg has two spurs at the tip. The third and largest leg segment (femur) on the front and middle legs are white in front, black in back. The hind legs are black except for the small first segment, which is white.

The wings are smoky and clear.

The male is slightly smaller, averaging ⅜″ (9 mm) in length. The antennae are often entirely black. The underside of the abdomen is often entirely white. It is otherwise similar to the female.

Total length: ⅜″

elderberry (Sambucus)

Sources

24, 30, 82, 83.

This species has no common name. The common name for the family Tenthredinidae is common sawflies, and it is applied here for convenience.

Location: Woodbury, Minnesota

Location: Woodbury, Minnesota