Family SCIARIDAE (Dark-winged Fungus Gnats) [Fig. 9]
Dark-winged fungus gnats are small delicate flies, 1.0 to 11 mm long, usually blackish, brownish or yellowish in colour. Head usually ovoid in shape, higher than long; compound eyes usually forming a dorsal bridge above antennal bases; frons with three ocelli; basal two segments of antenna globular, rest of antenna with 14 segments which are cylindrical, sessile or stalked; palps of one to three segments, the basal segment usually reduced in size; first distinct segment often with a sensory pit or with a group of sensory setae. Thorax with anterior pronotum setose; posterior pronotum sometimes with a few setae; scutum with bristles of variable length. Wings hyaline or smoky, sometimes reduced or absent; costal vein ending between apices of R5 and M1. Tibiae with one or two apical spurs; tarsal claws simple or toothed. Abdomen cylindrical, in females, usually strongly tapered posteriorly. Male terminalia exposed, often broader than rest of abdomen, and not usually rotated, but sometimes rotated up to 180° during copulation.
Adult dark-winged fungus gnats are usually found in moist places wherever fungus grows. Larvae generally feed on decaying plant material, animal excreta, or fungus. The family is worldwide in distribution with the exception of Antarctica. Some cosmopolitan species appear to have been spread synanthropically. There are over 1800 described extant species in about 90 genera worldwide with about 170 species in 18 genera known from the Nearctic.