Sciaridae
Encyclopedia
Sciaridae is 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. There are currently around 1700 described species but there are estimated to be up to 20,000 species awaiting discovery, mainly in the tropics
. More than 600 species are known from Europe
.
s are small, from one to at the very most seven millimetres long. They have a slender, darkly colored body and dark wings. However, the females of several species are wingless. Their long legs and antennae with 8 to 16 segments are typical of many gnats.
The slender whitish larva
e feature a sclerotized head capsule.
islands and mountainous regions above 4,000 metres. Others (like 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 diptera 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.
s. Sciarid larva
e are mainly found in soil
and plant litter
where they seem to feed mainly on fungi
and animal faeces. There are also species that mine in plant parts above and below the earth. The larvae play an important role in turning forest leaf litter into soil.
Adult females lay about 200 transparent eggs (each about one millimeter long) into moist soil. After about one week the larvae hatch. 90% of larvae are female. Up to 2,500 per m² can be found. Several species, especially Sciara militaris, can be found to migrate in processions of up to ten meters, containing thousands of individuals. These processions occur from May to June in central Europe. The larvae there pupate from July to August.
The adults with their characteristical dancing flight do not sting. They only ingest liquids and live only long enough to mate and produce eggs. They die after about five days.
The use of cedar wood
chips is one way to keep Sciaridae away from plants.
genome elimination, whereby the male passes on only the genetic material of his mother to his offspring. The functional result of this is similar to haplodiploidy, but via a very different mechanism.
deposits, the earliest known fossil
s dating from the Cretaceous
period.
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
, 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. There are currently around 1700 described species but there are estimated to be up to 20,000 species awaiting discovery, mainly in the tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
. More than 600 species are known from Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.
Description
These gnatGnat
A gnat is any of many species of tiny flying insects in the Dipterid suborder Nematocera, especially those in the families Mycetophilidae, Anisopodidae and Sciaridae.In British English the term applies particularly to Nematocerans of the family Culicidae...
s are small, from one to at the very most seven millimetres long. They have a slender, darkly colored body and dark wings. However, the females of several species are wingless. Their long legs and antennae with 8 to 16 segments are typical of many gnats.
Family Description (formal)
See http://delta-intkey.com/britin/dip/www/sciarida.htm and images at Diptera.infoThe slender whitish larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e feature a sclerotized head capsule.
Distribution
The Sciaridae occur worldwide, even in extreme habitats like antarcticAntarctic
The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...
islands and mountainous regions above 4,000 metres. Others (like 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 diptera 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.
Species lists
Life cycle
The life cycle of only a few species has been studied in any detail, mainly those which are pests of commercially grown mushroomMushroom
A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...
s. Sciarid larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e are mainly found in soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
and plant litter
Plant litter
Plant litter, leaf litter or tree litter is dead plant material, such as leaves, bark, needles, and twigs, that has fallen to the ground. Litter provides habitat for small animals, fungi, and plants, and the material may be used to construct nests. As litter decomposes, nutrients are released to...
where they seem to feed mainly on fungi
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
and animal faeces. There are also species that mine in plant parts above and below the earth. The larvae play an important role in turning forest leaf litter into soil.
Adult females lay about 200 transparent eggs (each about one millimeter long) into moist soil. After about one week the larvae hatch. 90% of larvae are female. Up to 2,500 per m² can be found. Several species, especially Sciara militaris, can be found to migrate in processions of up to ten meters, containing thousands of individuals. These processions occur from May to June in central Europe. The larvae there pupate from July to August.
The adults with their characteristical dancing flight do not sting. They only ingest liquids and live only long enough to mate and produce eggs. They die after about five days.
The use of cedar wood
Cedar wood
Cedar wood comes from several different trees that grow in different parts of the world, and may have different uses.* California incense-cedar, from Calocedrus decurrens, is the primary type of wood used for making pencils...
chips is one way to keep Sciaridae away from plants.
Mating and genetics
The Sciaridae practice paternalPaternalism
Paternalism refers to attitudes or states of affairs that exemplify a traditional relationship between father and child. Two conditions of paternalism are usually identified: interference with liberty and a beneficent intention towards those whose liberty is interfered with...
genome elimination, whereby the male passes on only the genetic material of his mother to his offspring. The functional result of this is similar to haplodiploidy, but via a very different mechanism.
Evolution
Sciarids are fairly common in amberAmber
Amber is fossilized tree resin , which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents...
deposits, the earliest known fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s dating from the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period.
External links
- Fungus Gnats Online
- Bradysia spp., darkwinged fungus gnats on the UFUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
/ IFASInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
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