What Bug Is That? The guide to Australian insect families.

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The Anisopodoidea is a worldwide, species-poor superfamily of  some 100 species of small to moderate-sized, long-legged flies. The wing is frequently patterned with dark markings, there are three ocelli on the head and the antenna  is well developed and non-plumose. The term 'window flies' has been used because some species can be conspicuous when they enter houses.

The taxonomic history of the Anisopodidae is complicated, including lack of agreement concerning the composition of the family, especially the status and relationships of the Mycetobiinae (non-Australian) and even the correct name for the nominate genus.

Here Amorim's classification is adopted, in which the superfamily Anisopodoidea comprises the Anisopodidae sensu stricto and the newly erected families Olbiogastridae and Mycetobiidae. However, both Olbiogastridae and Anisopodidae are largely plesiomorphic with respect to Mycetobiidae, and may very well represent a basal paraphyly.

Adult Anisopodoidea can be found close to the larval habitat, but certain species enter houses where their activity at windows has given rise to a vernacular name of 'window gnats'; however, in nature they may be found especially associated on wounded trees with running sap.


Anisopodoidea have wing cells m3 and Cup open to margin: R sometimes has three branches, but never has supernumerary crossvein or a closed cell between R2+3, and R4+5, cell d may be or absent; M has two or three branches; A1 is complete or incomplete.

In the Olbiogastridae, crossvein m-m is very short or obliterated, cell m1 appearing acute proximally, and macrotrichia are absent on wing veins bM, M, M1, M2, and CuA1.

In the Anisopodidae Cell m1 tapers proximally, but crossvein m-m is well-developed compared to the Olbiogastridae, and macrotrichia are present on all wing veins except A2.

Mycetobiidae is differentiated by wing cells br and bm being confluent: six veins thus arise from the combined basal cell.

The larvae of Anisopodidae are saprophagous, developing in a wide range of rotting vegetable matter, including slime-fluxes on trees and in dung. The larvae lack prolegs, have abdominal segments 2-6 divided into two unequal parts, and have a ventral perianal plate of darkened, thickened cells surrounding the anus.


Anispodidae are worldwide in distribution, excepting Antarctica.

Olbiogastridae are represented in Australia by a single, monotypic genus. Austrogaster insularis (Tonnoir, 1923), is known only from Lord Howe Island. A second, rare and undescribed species has been reported from Queensland.

Three species of Anisopodidae are known from Australia and Tasmania: Sylvicola dubius, S. funebris and S. neozelandicus . Mycetobiidae are represented by Valeseguya rieki Colless known from the Otway Ranges.

  • Anisopodidae

  • Anisopodidae

  • Anisopodidae