Insect guide > Flies > Snipe Flies

Snipe Flies

(Family Leptidae.)
These are slender, rather small flies, somewhat resembling the robber flies, on account of their long legs and slender bodies. They have usually smoky wings and velvety bodies, some of them slightly resembling yellow-banded wasps. They are not especially numerous. Some of these flies are predatory and destroy other insects and this may be the habit of all. They are sluggish in their habits and are easily caught. The larvae are predaceous, and variable in their habitations. Some are found in water, others live in decaying wood, or in the earth, in moss, in dry sand, or in the burrows of wood-boring beetles.

There is a curious resemblance between the habits of the species of the genus Vermileo and the well-known ant-lions, the larvae forming conical pitfalls in the sand in which to catch small insects. Flies of the genus Atherix lay their eggs, as do the females of the Stratiomyiid genus Odontomyia, in masses on dried branches overhanging the water. The masses become very large and pear-shaped from the curious fact that a number of females add their eggs to the same mass, frequently dying after egg laying and leaving their bodies attached to the egg mass. The larvae are cylindrical and sometimes bristly, and may have fleshy appendages resembling prologs on the abdomen. Atherix has seven pairs of these prologs. The larva of one species has been found by Hart in damp earth.

The families Xylophagidae and Coenomyiidae which will be found mentioned in some books are merged with the Leptids.
The Xylophagids are rather slender flies with the abdomen pointed in the female sex. The Coenomyiids on the contrary are stout, rather large flies. The larvae of some of Xylophagids live under bark and prey on other insects and the larvae of Coenomyia live in the earth and are also probably predaceous.

Nearly three hundred species are known, or which rather more than fifty occur in the United States, but the full life history of none of our American forms is known. Vermileo, the form whose larva resembles that of the ant-lion, does not occur in the United States.