Sciaridae

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Sciaridae
Sciara hemerobioides - Flickr - gailhampshire.jpg
Sciara hemerobioides
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Superfamily: Sciaroidea
Family: Sciaridae
Billberg, 1820 [1]
Diversity
at least 90 genera
A sciarid ovipositing into a leaf of Urtica

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 similarity among species. [2]

Contents

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. [3]

Description

Adult Sciaridae are small, dark flies 1–11 mm long and usually <5 mm long. [4] They have a characteristic wing venation: there is no cross vein except for a short rs at the wing base, the anterior veins are a short R1 and a long R5, vein M has a simple fork with a long stem, and CuA1 has a fork with a short stem. [5]

Larval Sciaridae are slender and lack legs. They are white except for a black head, and their skin is slightly transparent so the contents of the gut are visible. [4] The abdominal creeping welts lack sclerotised spicules; this differentiates Sciaridae from the related family Mycetophilidae, in which sclerotised spicules are present. [6]

Distribution

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.

Life cycle

Sciarid larva Sciara.hemerobioides.larva.jpg
Sciarid larva

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 often occur in decaying plant matter such as rotten wood or under the bark of fallen trees, but can also be found in animal feces or fungi. [2] The species Austrosciara termitophila is an inquiline in termite nests while the genus Vulagisciara is a guest in ant-plants of family Rubiaceae. [2] 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.

Adult females lay about 200 transparent eggs (each about 1 mm; 132" long) into moist soil. After about one week, the larvae hatch. About 90% of the larvae are female. Up to 2,500 per m² (230 per sq. ft.) can be found. Several species, especially Sciara militaris , can be found to migrate in processions of up to 10 metres, containing thousands of individuals. These processions occur from May to June in central Europe. Occurrences have been reported e.g. in Southern Poland, the Polish name of the phenomenon is "pleń". The larvae there pupate from July to August.

The adults with their characteristic dancing flight do not bite. They only ingest liquids and live only long enough to mate and produce eggs. They die after about five days.

Mating and genetics

Sciaridae practice paternal 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. [7]

Evolution

Sciarids are fairly common in amber deposits, with the earliest known fossils dating from the Cretaceous period. [8]

Sciarid fly in amber 2007 01 3000 muchowka sciaridae.jpg
Sciarid fly in amber
Dark-winged fungus gnat, Sciaridae Sciaridae P1640835a.jpg
Dark-winged fungus gnat, Sciaridae
Dark-winged fungus gnat, Sciaridae, male Sciaridae goldenrod male.jpg
Dark-winged fungus gnat, Sciaridae, male

Pest status

Sciarid flies are common pests of mushroom houses and of plants grown in protected culture, for example herbs, where the warm and moist conditions favour their rapid development. In commercial mushroom houses, sciarid fly larvae tunnel into the stalks of the mushrooms, and feeding damage can sever developing mycelium, causing mushrooms to become brown and leathery. Their faeces may also prevent the mycelium from colonising the casing layer, severely reducing yields. As a pest of plants, sciarid larvae feed on the root system. In both industries, adult sciarid flies are a nuisance pest that can result in crop rejection if high numbers are present in the growing area.

The damaging larval stage can be controlled using the beneficial nematode Steinernema feltiae, which enters the larva and releases a bacterium ( Xenorhabdus sp.) that kills the insect. The nematode then reproduces within the larva and its young are released into the growing medium, where they actively search out new host larvae (infective juveniles). [9]

See also

Related Research Articles

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The Bibionomorpha are an infraorder of the suborder Nematocera. One of its constituent families, the Anisopodidae, is the presumed sister taxon to the entire suborder Brachycera. Several of the remaining families in the infraorder are former subfamilies of the Mycetophilidae, which has been recently subdivided. The family Axymyiidae has recently been removed from the Bibionomorpha to its own infraorder Axymyiomorpha.

<span class="mw-page-title-main">Phoridae</span> Family of flies

The Phoridae are a family of small, hump-backed flies resembling fruit flies. Phorid flies can often be identified by their escape habit of running rapidly across a surface rather than taking to the wing. This behaviour is a source of one of their alternate names, scuttle fly. Another vernacular name, coffin fly, refers to Conicera tibialis. About 4,000 species are known in 230 genera. The most well-known species is cosmopolitan Megaselia scalaris. At 0.4 mm in length, the world's smallest fly is the phorid Euryplatea nanaknihali.

<i>Leptoconops torrens</i> Species of fly

Leptoconops torrens is a species of small biting flies in the no-see-um family Ceratopogonidae. They were first mentioned in writing by Charles Henry Tyler Townsend in 1893. The name Leptoconops carteri is a junior synonym of L. torrens. They are prevalent in the southwestern and southeastern areas of the United States. In early stages of life, L. torrens flies dwell in soil, then emerge to feed and breed as fully developed adults.

<span class="mw-page-title-main">Nematocera</span> Suborder of flies

The Nematocera are a suborder of elongated flies with thin, segmented antennae and mostly aquatic larvae. This group is paraphyletic and contains all flies but species from suborder Brachycera, which includes more commonly known species such as the housefly or the common fruit fly. Families in Nematocera include mosquitoes, crane flies, gnats, black flies, and multiple families commonly known as midges. The Nematocera typically have fairly long, fine, finely-jointed antennae. In many species, such as most mosquitoes, the female antennae are more or less threadlike, but the males have spectacularly plumose antennae.

<span class="mw-page-title-main">Fungus gnat</span> Group of insects

Fungus gnats are small, dark, short-lived gnats, of the families Sciaridae, Diadocidiidae, Ditomyiidae, Keroplatidae, Bolitophilidae, and Mycetophilidae ; they comprise six of the seven families placed in the superfamily Sciaroidea.

<span class="mw-page-title-main">Stratiomyidae</span> Family of flies

The soldier flies are a family of flies. The family contains over 2,700 species in over 380 extant genera worldwide. Larvae are found in a wide array of locations, mostly in wetlands, damp places in soil, sod, under bark, in animal excrement, and in decaying organic matter. Adults are found near larval habitats. They are diverse in size and shape, though they commonly are partly or wholly metallic green, or somewhat wasplike mimics, marked with black and yellow or green and sometimes metallic. They are often rather inactive flies which typically rest with their wings placed one above the other over the abdomen.

<span class="mw-page-title-main">Mycetophilidae</span> Family of flies

Mycetophilidae is a family of small flies, forming the bulk of those species known as fungus gnats. About 3000 described species are placed in 150 genera, but the true number of species is undoubtedly much higher. They are generally found in the damp habitats favoured by their host fungi and sometimes form dense swarms.

<span class="mw-page-title-main">Scatopsidae</span> Family of flies

The minute black scavenger flies or "dung midges", are a family, Scatopsidae, of nematoceran flies. Despite being distributed throughout the world, they form a small family with only around 250 described species in 27 genera, although many await description and doubtless even more await discovery. These are generally small, sometimes minute, dark flies, generally similar to black flies (Simuliidae), but usually lacking the humped thorax characteristic of that family.

<i>Delia</i> (fly) Genus of flies

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<i>Coenosia attenuata</i> Species of fly

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Hypoaspis is a genus of mites in the family Laelapidae.

<span class="mw-page-title-main">Sciaroidea</span> Superfamily of flies

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<i>Tirathaba rufivena</i> Worms that eat oil-/coconut-palm flowers

Tirathaba rufivena, the coconut spike moth, greater coconut spike moth or oil palm bunch moth, is a moth of the family Pyralidae. It is found from south-east Asia to the Pacific islands, including Malaysia, the Cook Islands, the Philippines and the tropical region of Queensland, Australia. They are considered as a minor pest.

Bradysia austera is a species of fungus gnat found in the British Isles.

Bradysia ismayi is a species of fungus gnat found in the British Isles.

Bradysia nigrispina is a species of fungus gnat found in the British Isles.

<span class="mw-page-title-main">Gnat</span> Any of many species of tiny flying insects in the dipterid suborder Nematocera

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. They can be both biting and non-biting. Most often they fly in large numbers, called clouds. "Gnat" is a loose descriptive category rather than a phylogenetic or other technical term, so there is no scientific consensus on what constitutes a gnat. Some entomologists consider only non-biting flies to be gnats. Certain universities and institutes also distinguish eye gnats: the Smithsonian Institution describes them as "non-biting flies, no bigger than a few grains of salt, ... attracted to fluids secreted by your eyes".

<i>Bradysia ocellaris</i> Species of fly

Bradysia ocellaris is a species of fly in the family Sciaridae. It is found in the Palearctic. It has also been introduced to Australia. It feeds on fungi, and larvae can feed on cultivated plants in greenhouses.

The mushroom phorid fly(Megaselia halterata) is a species of scuttle fly or hump-backed flies in the family Phoridae. "The mushroom phorid" is also used to refer to M. halterata. Megaselia halterata is a common pest of mushroom cultivation, attracted by the aroma of developing fungal mycelium. The larvae damage both the mushroom mycelium and gill tissues. Megaslia halterata can be found worldwide.

<i>Bradysia</i> Genus of flies

Bradysia is a genus of fungus gnat in the family Sciaridae. They are commonly known as darkwinged fungus gnats. They are considered a major pest in greenhouse agriculture because they thrive in the moist conditions common inside greenhouses and feed on the plants being grown within. Bradysia is a large genus containing over 500 living species, with at least 65 species found in North America and 172 in Europe.

References

  1. Billberg, G.J. (1820). Enumeratio insectorum in Museo Gust. Stockholm: Joh. Billberg. pp. 138 pp.
  2. 1 2 3 "broadley". hbs.bishopmuseum.org. Retrieved 2022-07-02.
  3. Mohrig, Werner (2003). "Black fungus gnats of Central America. Part I. (Diptera, Sciaridae)" (PDF). Beiträge zur Entomologie. 53 (1): 1–69. doi:10.21248/contrib.entomol.53.1.1-69 . Retrieved 13 May 2022.
  4. 1 2 "Family Sciaridae - Dark-winged Fungus Gnats". bugguide.net. Retrieved 2022-07-02.
  5. Mohrig, W; Heller, K; Hippa, H; Vilkamaa, P; Menzel, F (July 2013). "Revision of Black Fungus Gnats (Diptera: Sciaridae) of North America". Studia dipterologica. 19: 141–286.
  6. Ebrahim, Ayman (2010-06-01). "An illustrated Key to the larval stages of dipterous families in Egypt". Egyptian Academic Journal of Biological Sciences. A, Entomology. 3 (1): 145–172. doi: 10.21608/eajbsa.2010.15251 . ISSN   2090-0813.
  7. Featherston, R.; Jones, T. M.; Elgar, M. A. (2013). "Female resistance behaviour and progeny sex ratio in two Bradysia species (Diptera: Sciaridae) with paternal genome elimination". Journal of Evolutionary Biology. 26 (5): 919–928. doi:10.1111/jeb.12117. PMID   23621366. S2CID   37504934.
  8. "Sciaridae -- fossil Diptera cat". hbs.bishopmuseum.org. Retrieved 2022-07-02.
  9. Gouge, Dawn H.; Hague, N G M. (1995). "The development of Steinernema feltiae (Nematoda Steinernematidae) in the sciarid fly Bradysia paupera (Diptera: Sciaridae)". Annals of Applied Biology. 126 (2): 395–401. doi:10.1111/j.1744-7348.1995.tb05374.x. ISSN   0003-4746.