Drone flies

Eristalis is a genus of hover flies. There are 106 Eristalis species worldwide, 20 species in North America north of Mexico, and at least 10 species in Minnesota.

The larvae, known as rat-tailed maggots, are aquatic. They live in polluted water or in wet carcasses. They feed on small organisms.

Adults are found from April to October in a variety of habitats with flowers. They feed on flower nectar.

The genus Eristalis is easily identified. A few species are bumble bee mimics and are also readily identifiable. Several species resemble male (drone) honey bees. This is the feature that gives the genus its common name. Identification of some species requires careful examination of characters that are difficult to interpret.

Eristalis adults are large flies. The body is robust and moderately to densely hairy. The head is at least as broad as the thorax. The antennae are short and are inserted near the middle of the head. The third segment is flat and longest on the bottom, shorter and rounded on top. The arista is not feather-like (plumose). The scutellum is not fringed. The abdomen is black and has yellow markings on most species. On the wing, there is a spurious vein between the radius (R) and media (M) veins. The marginal and R₁ cells are closed. The R₄₊₅ vein is deeply bent (sinuous). The femurs on the hind leg is unarmed, with no spurs, spines, or teeth.

The larvae are aquatic. They breath through a long, snorkel-like appendage. This is the feature that gives the tribe its common name.