The Anisopodidae are a small

cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953 Hotels and resorts * Cosmopoli ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

gnat 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 ...

-like

flies Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced m ...

known as wood gnats or window-gnats, with 154 described

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

species in 15 genera, and several described fossil taxa. Some species are

saprophagous Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi (f ...

or fungivorous. They are mostly small to medium-sized flies, except the genera ''Olbiogaster'' and ''Lobogaster'', which are large with bizarrely spatulated abdomens. Their phylogenetic placement is controversial. They have been proposed to be the sister group to the higher flies, the

Brachycera The Brachycera are a suborder of the order Diptera. It is a major suborder consisting of around 120 families. Their most distinguishing characteristic is reduced antenna segmentation. Description A summary of the main physical characteristics i ...

. Some authors consider this group to be four distinct families – Anisopodidae, Mycetobiidae, Olbiogastridae, and Valeseguyidae. Sylvicola wing veins

Description

For terms see Morphology of Diptera. Authors disagree on the

circumscription Circumscription may refer to: *Circumscribed circle * Circumscription (logic) *Circumscription (taxonomy) *Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthrop ...

of this taxon. Published accounts differ. The Anisopodidae are small or medium-sized (mostly 4–12 mm, ''Lobogaster'' found in Chile 17–18 mm) yellowish to brownish gnats with long, thin legs. The tibiae have apical spurs. The head is small and rounded and with small mouthparts. The eyes are dichoptic or holoptic. Ocelli are present and form an equilateral triangle. The slender antennae vary from relatively short to longer than head and thorax together. The antennae have 14-16 segments. The mesonotum is without a transverse suture; the wing is wide, with a clear anal lobe and a pattern of smaller markings (sometimes hyaline). The alula is strongly differentiated in ''Olbiogaster'' and ''Sylvicola''. Both wings lie flat over the abdomen in the resting position. A pterostigma is present or absent, and the wing membrane is densely covered with microtrichia (macrotrichia present in ''Sylvicola''). The costa (C) ends at or just beyond the tip of R4+5. The subcosta (Sc) ends in the costa near the middle of wing and distal to base of Rs. The stem of R is straight (sometimes with an interruption or weakening below crossvein h). Rs arises near but proximal to the middle of the wing, with two branches. R4+5 is long, ending near tip of wing; crossvein r-m is situated near or distal to the fork of Rs. Radial vein 2+3 (R2+3) may end in R1 or end in the costa. The median vein (M) has three or two branches and the discal cell (d) is present or absent. CuA2 is straight or sinuous distally. CuA1, CuA2, and A1 all reach the wing margin. CuP when present is variably distinct; A2 is present but weak apically. The abdomen is slender.F. Christian Thompson, 2005 New Mesochria species (Diptera: Anisopodidae) from Fiji, with notes on the classification of the family In Fiji Arthropods IV. Edited by Neal L. Evenhuis & Daniel J. Bickel. Bishop Museum Occasional Papers 86: 11–21 (2006).

Identification

*Online-Keys:
The Palaearctic species of Sylvicola
*Coe, R.L., Freeman, P., & Mattingly, P.F. (1950) Diptera: Nematocera, families Tipulidae to Chironomidae. Royal Entomological Society of London Handbook 9(2)ii
pdf
*Shtakel'berg, A.A. Family Anisopodidae (Rhyphidae, Phryneidae) in Bei-Bienko, G. Ya, 1988 ''Keys to the insects of the European Part of the USSR'' Volume 5 (Diptera) Part 2 English edition. Keys to Palaearctic species but now needs revision. * Séguy, E. (1940) Diptères: Nématocères. Paris: Éditions Faune de Franc
Bibliothèque virtuelle numérique

References

Species lists

West Palaearctic including RussiaJapanWorld list

External links

Anisopodidae taxonomyDiptera.info
Images
Family Anisopodidae at EOL
images {{Taxonbar, from=Q1404907 Nematocera families