snipe fly

Chrysopilus foedus is a small to medium-sized, early season, snipe fly. It occurs in the Midwestern United States in Indiana, Illinois, Iowa, Kansas, Minnesota, Nebraska, South Dakota, and Wisconsin. It is found in late spring, mostly in May, on roadsides, perched on vegetation on stream sides, and perched everywhere in open places.

Chrysopilus larvae may be aquatic, living in water and associated with stream-side vegetation. Or they may live in moist, rich soil, prey on worms and soft-bodied insect larvae, and eat the eggs of grasshoppers. Little is known of the biology of adult Chrysopilus. They have been reported as preying on other small insects, but this is unlikely.

Adults are black with highly contrasting markings. Females are ⅜ to 7⁄16″ (9 to 11 mm) in length. Males are smaller, 5⁄16″ to ⅜ (7.5 to 9.5 mm) in length.

On the male, the front of the head and the face are light grayish, and there are long, pale hairs on the sides of the face. The sides of the front are concave, not parallel. On the female, the top of the head (vertex), the front of the head, and the face are brown, and the hairs on the sides of the face are darker. There are two large compound eyes on the side of the head and three small simple eyes (ocelli) in a triangle on a low, raised, knob-like projection (tubercle) on top of the head. The compound eyes are hairless. There is a groove across each compound eye clearly separating the lower, smaller facets from the upper, larger facets. On the female, the compound eyes are widely separated at the top of the head. On the male, they are very narrowly separated at the top of the head. At the closest point the distance between them is about one-half the width of the occelar tubercle. The antennae are blackish, and they have three segments. The third segment is cone-shaped or onion-shaped, rounded but compressed at the base and the tip. It has a slender bristle (arista) at the tip. The aristae are distinctly longer than the antennae.

The thorax is black, it has three segments, and it is covered with pale yellowish to silvery hairs. The sides of each segment, including the third, are covered with similar but longer hairs. The balancing organs (halteres) are yellowish with dark brownish or blackish knobs at the tip. The plate between the wing bases (scutellum) is brownish or blackish, and it is covered with long yellowish or silvery hairs.

The abdomen on the male is narrow and tapered. On the female it is broad and is tapered at least on the lower half. Each abdominal segment is black on the front half and has a distinct band of silvery to yellowish hair on the rear half. The hairs on the upper surface often wear off with age.

The wings are distinctly narrowed and stalk-like (petiolate) at the base. Both the main (longitudinal) veins and the cross veins are heavily bordered brownish. The costal cell, the first basal cell, and sometimes most of the radial cell are tinted brownish. Aside from these areas the wings are clear. The fourth posterior cell is open, and the anal cell is closed.

The legs are long and mostly brownish yellow. On the front and middle legs, the third segment (femur) is dark at the base, and it is sometimes mostly dark. The hind femur is brownish or sometimes completely brownish yellow. The fourth segment (tibia) on each middle leg has 2 spurs at the tip. On the hind legs the tibiae have 1 spur, and on the front legs they have no spurs. The last part of each leg (tarsus), corresponding to the foot, has 5 segments. The tip of the first segment and all of the remaining segments are dark brownish or blackish brown. The last segment has a pair of claws at the tip and 3 pads between the claws.

Total length: 5⁄16″ to 7⁄16″ (7.5 to 11 mm)

Roadsides, stream sides, and open places

May

Worms, soft-bodied insect larvae, and eggs of grasshoppers

Unknown

Sources

29, 30, 82, 83.

Scattered but locally abundant

Infraorder
Orthorrhapha was historically one of two infraorders of Brachycera, a suborder of Diptera. However, Brachycera did not contain all of the descendants of the last common ancestor (paraphyletic). It was split into five extant (still existing) and one extinct infraorder. Orthorrhapha is now considered obsolete and has not been used in decades, but it persists in printed literature and on some online sources. A recent revision of the order Diptera (Pope, et al., 2011) revived the name Orthorrhapha, but this has not been widely accepted.

Subfamily
The genus Chrysopilus was formerly included in the subfamily Rhagioninae. In 1903 it was separated with five other genera into the new subfamily Chrysopilinae, but this was ignored by most authors. A recent molecular and morphological analysis of the family Rhagionidae (Kerr, 2004) supported the separation of the subfamily Chrysopilinae to include Chrysopilus and two other genera.

This species has no common name. The common name of the Family Rhagionidae is snipe flies, and it is applied here for convenience.

Chrysopilus foedus snipe fly

On May 13, 2024, I found/photographed Chrysopilus foedus at Barnes Prairie hedgerow, Racine Co., WI.

Babette Kis
5/13/2024

Location: Barnes Prairie, Racine Co., WI

On May 13, 2024, I found/photographed Chrysopilus foedus at Barnes Prairie hedgerow, Racine Co., WI.