Sciaroidea is asuperfamily in the infraorderBibionomorpha. There are about 16 families and more than 15,000 described species in Sciaroidea. Most of its constituent families are variousgnats (e.g.fungus gnats).
Asnematoceran flies, sciaroid adults generally have long segmentedantennae, while their larvae have a well-developed head and mouthparts.[2]
Aside from this, sciaroids vary in appearance. For example,Sciaridae adults have each eye extended dorsally to form an "eye bridge", a feature not found in related families.[3]Cecidomyiidae adults have a distinctive reduced wing venation, while their larvae are atypical for nematoceran larvae in having a very small head capsule.[4]
Most fungus gnats (Sciaroidea excluding Cecidomyiidae) live in forests with their larvae occurring in fungi, dead wood and soil. There are some which live in wetlands such asfens.[5] Several genera of Sciaridae and Mycetophilidae may reach high abundances in damp buildings with wet organic matter.[6]
Some species of Sciaridae and Cecidomyiidae are among the rare Diptera that spend their entire lives in soil. These arewingless as adults.[7]
Sciaroid larvae typically feed onfungi but there are some which form plantgalls (many Cecidomyiidae) or prey on other invertebrates (Keroplatidae).[8]
^Jaschhof, M.; Didham, R. K. (2002). "Rangomaramidae fam. nov. from New Zealand and implications for the phylogeny of the Sciaroidea (Diptera: Bibionomorpha)".Studia Dipterologica Supplement.11:1–60.