Perissommatidae


The Perissommatidae are a family of flies that was proposed in 1962 by Donald Colless based on the species Perissomma fusca from Australia. The family now includes five species, four from Australia and one from Chile. The Perissommatidae are unusual as appear to have four compound eyes. They have a small slender body less than 2 mm in length. Their wings are large in comparison to their bodies and subsequently their flight is weak. Preferring high-altitude forest environments, adults only fly in the winter. The larvae live in decaying leaf litter in wet sclerophyll or cool rain forests. Some species are suspected to be associated with fungi. In the case of Perissomma macalpinei, numbers of adults have been observed congregate in clumps of foliage, rising in short, zigzag flights in the sunlight above the foliage for short periods before descending.
A fossil from the Jurassic 164-165 mya from China Perissordes pilosus has been placed in the family as are several genera from the Mesozoic in the Transbaikalia and Mongolian region.