In a coastal rainforest, a tropical crane fly (Tipulidae) rests on a leaf. 

Morretes, Paraná, Brazil
A hover fly sits on its perch.

Urbana, Illinois, USA
Prochyliza xanthostoma, the waltzing fly.

Urbana, Illinois, USA
A vinegar fly (Drosophilidae) circles in to land on a shelf fungus. 

Cape Tribulation, Queensland, Australia
A vinegar fly (Drosophilidae) circles in to land on a shelf fungus. Note the iridescent patterning on the wing. These metallic colors were recently discovered to be species-specific and potentially involved in communication.

Cape Tribulation, Queensland, Australia
Homoneura (Homoneura) sp. (Lauxaniidae)

Cape Tribulation, Queensland, Australia
Bristle Fly - Tachinidae

Urbana, Illinois, USA
A tiny frit fly (Chloropidae: Conioscinella) steals a bit of hemolymph from the kill of an assassin bug (Reduviidae: Sinea).

East Brooklyn, Illinois, USA
Larvae of syrphid flies in the genus Microdon are so odd that they were originally described as molluscs.  The adults are more or less normal-looking flies, but larvae are predators of ant brood, living within the dark galleries of ant nests (in this case, with Linepithema oblongum).

Termas de Reyes, Jujuy, Argentina
A vinegar fly (Drosophilidae) circles in to land on a shelf fungus. Note the iridescent patterning on the wing. These metallic colors were recently discovered to be species-specific and potentially involved in communication.

Cape Tribulation, Queensland, Australia
A vinegar fly (Drosophilidae) circles in to land on a shelf fungus. Note the iridescent patterning on the wing. These metallic colors were recently discovered to be species-specific and potentially involved in communication.

Cape Tribulation, Queensland, Australia
A vinegar fly (Drosophilidae) circles in to land on a shelf fungus. Note the iridescent patterning on the wing. These metallic colors were recently discovered to be species-specific and potentially involved in communication.

Cape Tribulation, Queensland, Australia
See photo in original gallery.
all images and text © Alex Wild 2001-2013