Dolichopodidae, the
long-legged flies, are a large,
cosmopolitan family of
true flies with more than 7,000 described
species in about 230
genera. The genus
Dolichopus is the most speciose, with some 600 species. Dolichopodidae generally are small flies with large, prominent eyes and a metallic cast to their appearance, though there is considerable variation among the species. Most have long legs, though some do not. In many species the males have unusually large
genitalia which are taxonomically useful in identifying species. Most adults are
predatory on other small animals, though some may scavenge or act as kleptoparasites of spiders or other predators.