American snout fly

Description

Rhingia is a genus of small to medium-sized hover flies. There are at least 24 Rhingia species worldwide. Rhingia nasica (American snout fly) is the only member of the genus that occurs in North America.

American snout fly is a common, small to medium-sized, hover fly. It occurs in the United States from Maine to northern Georgia, west to Minnesota and Arkansas, and in southern Canada from Nova Scotia to Alberta.

Adults are active from May to September. They are found in deciduous forests, bogs, and fens. They feed on the nectar of a variety of flowers, including aster, brambles, geranium, goldenrod, knapweed, touch-me-not, and violet. The larvae are thought to be associated with the dung of large, plant-eating animals. They have been associated with cow dung.

Adults are ¼″ to ⅜″ (6 to 9 mm) in length.

The head is hemispherical and wider than the thorax. The face has a distinct, long, forward-directed snout. The antennae are short, they have three segments, and they are inserted well above the middle of the face. There is a long bristle (arista) on the upper side of the third segment. The arista is longer than the antennae and it is very slightly hairy, almost hairless. The compound eyes are hairless. On the male they meet at the top of the head for a long distance. On the female they are well separated.

The thorax is black and rectangular, almost square. The large exoskeletal plate (scutum) covering the middle segment of the thorax has three gray longitudinal stripes. The two lateral stripes are complete, extending from the rear margin to the front margin. The middle stripe is partial, extending from the rear margin just halfway to the front. The small plate covering the rear part of the middle segment (scutellum) is yellowish and more or less translucent. There are no bristles on the scutum or scutellum. The small plate in the shoulder area just behind the head (postpronotum) is hairy.

The abdomen is short and wide. It is convex when viewed from above.

The wings are clear, unmarked, and lightly tinted brown. The vein on the leading edge (costa) and the vein R₄₊₅ end well before the wingtip.

Size

Total length: ¼″ to ⅜″ (6 to 9 mm)

Similar Species

Habitat

Deciduous forests, bogs, and fens

Ecology

Season

May to September

Behavior

Life Cycle

Larva Food/Hosts

Large herbivore dung

Adult Food

Flower nectar