Insect of the Day: Crane Fly

A Crane Fly
Notice there is only a single pair of wings. The second pair are highly modified into structures called "halteres". The halteres can be seen in the photograph just behind the wings. They look like miniature Tootsie Pops, if you remember those.
The wing span of this Crane Fly is a little over an inch.
(Click on the photo to enlarge it; the halteres are then easier to see.)

Spring is the time of year when Crane Flies are most commonly seen. Many people think they are giant mosquitoes, but these flies do not bite. In fact, most of them live only a few days. Long enough to mate, lay eggs and die.

Crane Flies are "true" flies -- they have only one pair of wings. The second pair is highly modified to form a pair of structures called halteres. When the fly is flying the halteres are constantly vibrating. As the fly moves in space the moving halteres act like a gyroscope, enabling the fly to sense the position of its body in space and correct it to the desired flight path. (The Wikipedia page on Halteres explains this function in considerable depth.) 

The larvae of these flies feed on decomposing vegetation. I've found them in decaying leaves when I've cleaned out the gutters on our house and you can also find them in compost piles.

Besides being mistaken for mosquitoes, Crane Flies are sometimes confused with Daddy Long Legs because of their long, gangly legs. (Daddy Long Legs don't have wings and are not even Insects. Insects have three pairs of legs; Daddy Long Legs have four pairs.)