calypter

Wings of this fly are specialized having a sharp bend halfway through the wing and they are also known to have a well-developed calypter.

(as well as hairs on the rear margin of the calypter as in most Syrphini)

Most of the Muscomorpha are further subdivided into the Acalyptratae and Calyptratae based on whether or not they have a calypter (a wing flap that extends over the halteres).

It consists of those flies which possess a calypter that covers the halteres, among which are some of the most familiar of all flies, such as the house fly.

It can be distinguished from other genera of the tribe Syrphini because it is the only genus that has long hairs on the upper surface of the lower lobe of the calypter.

A calypter is either of two posterior lobes of the posterior margin of the forewing of flies between the extreme posterior wing base and the alula, which covers the halteres.

The distinguishing characteristics of this subfamily are: the stem vein is bare, the lower calypter and the proepisternal depression are bristly, but the suprasquamal region is bare or with only a few random bristles.

In flies (Diptera), the alula is a lobe of the posterior margin of the wing bounded proximally by the upper calypter, distally by the axillary incision, and anteriorly by the base of the anal vein.

As adults, the genus Lucilia is characterized by a shining green, blue, or bronze thorax and abdomen, a suprasquamal ridge (the ridge above the squamal lobes at the base of the wings) with setae, and no hair on the lower calypter.