*whew* Nevermind. Apparently they don't really prey on mosquitoes.

"Ecology
Despite their common names, crane flies do not prey on mosquitoes
as adults, nor do they bite humans. Some larval crane flies may on
occasion feed on mosquito larvae.[1] Adult crane flies feed on
nectar or they do not feed at all; most crane fly species live only
to mate and die once they become adults. Their larvae, called
"leatherjackets" or "leatherjacket slugs" because of the way they
move, consume roots (such as those of turf grass in backyard lawns)
and other vegetation, in some cases causing damage to plants.
Therefore the crane fly is occasionally considered a mild turf pest
in some areas.

The juvenile biology of many crane fly species is little known. The
larvae of less than 2% of the species have been described. Of those
that have been described, many prefer moist environments, and some
leatherjackets are aquatic.

The long legs are an adaptation to allow the fly to alight in
grassy places.

Crane flies serve as a food source for many birds."

http://en.wikipedia.org/wiki/Crane_fly