Perissommatidae is a family of Diptera

Diptera

Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...

 that was newly proposed in 1962. The family contains five species, four from Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and one from Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

. Perissommatidae are unusual as they have four eyes. They have a small slender body that's less than 2mm in length. Their wings are large in comparison to their body and subsequently their flight is weak. Preferring high altitude forest environments, adults only fly in the winter. 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 back.

External links

• Short account By Evenhuis, N. L. http://hbs.bishopmuseum.org/aocat/pdf/13perisso.pdf