Sciaridae

The Sciaridae are a family of flies, commonly known as dark-winged fungus gnats. Commonly found in moist environments, they are known to be a pest of mushroom farms and are commonly found in household plant pots. This is one of the least studied of the large Diptera families, probably due to the small size of these insects and the difficulty in specific identification. Currently, around 1700 species are described, but an estimated 20,000 species are awaiting discovery, mainly in the tropics. More than 600 species are known from Europe. These gnats are small, typically from one to seven millimetres long. They have slender, darkly coloured bodies and dark wings. However, the females of several species are wingless. Their long legs and antennae with eight to 16 segments are typical of many gnats. See and images at Diptera.info The slender whitish larvae feature a sclerotized head capsule. The Sciaridae occur worldwide, even in extreme habitats such as subantarctic islands and mountainous regions above 4,000 m. Others (such as Parapnyxia) are found in deserts, where they dig into the sand at extreme temperatures. Several species live exclusively in caves. However, most species live in forests, swamps, and moist meadows, where they live in the foliage. They are also often found in flowerpots. In moist and shadowy areas, up to 70% of all dipteran species can be Sciaridae. They are distributed through wind and drifting, for example on dead wood, and are often introduced by humans, by means of transported humus or similar. The life cycle of only a few species has been studied in any detail, mainly those which are pests of commercially grown mushrooms. Sciarid larvae are mainly found in soil and plant litter, where they seem to feed mainly on fungi and animal faeces. Also, some species mine in plant parts above and below the earth. The larvae play an important role in turning forest leaf litter into soil.