Species name: Eristalis tenax (L.)
Family: Syrphidae

The larvae of a few species of Syrphidae are encountered around animal production facilities and are readily recognized. As the name rat-tailed implies, the larvae are large, cylindrical, with a long narrow caudal projection, at the end of which is a pair of posterior spiracles surrounded by a rosette of hairs.

Rat-tailed maggot larvae are found in liquid habitats heavily polluted with manure. They are often encountered in runoff ditches and pools around dairy operations, as well as in waste lagoons for dairy, swine and poultry.

The most common species is Eristalis tenax, although others may be encountered, including some species in the closely-related genus Eristalinus (the adults of which are darker colored than those of Eristalis ).

The adults of E. tenax, known as drone flies, are clothed in dense short yellow hairs, giving the appearance of a large honey bee.

The antennae are short, with the third segment rounded or oval with a nonplumose arista. The eyes are pilose (hairy).

Wing venation is the typical form for the family Syrphidae, with the most distinctive characteristic being a longitudinal crease (false vein) through the middle of the wing.