Winter mosquitoes

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Winter mosquitoes
Trichocera hiemalis

Trichocera hiemalis

Systematics
Class : Insects (Insecta)
Order : Fly (Diptera)
Subordination : Mosquitoes (Nematocera)
Partial order : Tipulomorpha
Superfamily : Trichoceroidea
Family : Winter mosquitoes
Scientific name
Trichoceridae
Rondani , 1841

The winter mosquitoes (Trichoceridae) are a family of the two-winged birds (Diptera) and belong to the mosquitoes (Nematocera). Their species are specially adapted to cold climates. The family is spread almost worldwide, but is absent in Africa.

features

Trichocera annulata (detail: the male genital appendages)

The Trichoceridae are slender and long-legged, gracefully built mosquitoes. They reach a body length of about 3 to 8 millimeters.

The round to elongated head carries adapted to leaking diet mouthparts . Two large, pillow-like lip pads (labella) have a system of furrows on the surface, with which liquids can be absorbed by capillary action; the labellas can be folded out and are folded upwards in the resting position. They are very large in Trichocera and smaller in some other genera, so that the sharp tips of the labrum and hypopharynx remain visible when in a resting position . The labial palps are five-membered and elongated, they can reach twice the length of the head capsule; its first link is always very short. The antennae are always long, and when put back they reach at least the end of the thorax. Their base limb (scapus) is short and cylindrical, the small reversible limb (pedicellus) round and slightly wider. The antennae have 16 flagella members, elongated oval to cylindrical. In addition to the complex eyes, there are always three point eyes ( ocelles ).

The massive trunk section (thorax) protrudes above the small head, which gives the animals a hunched appearance. The overhead transverse seam (typical feature of the Tipuloidea ) is interrupted (incomplete) in the winter mosquitoes of the subfamily Trichocerinae. In both males and females, the wings always protrude above the tip of the abdomen when at rest. Their shape varies from elongated with a clear anal lobe ( Trichocera ) to rounded without such ( Paracladura ). In the Flügeladerung typical are the Analadern , both are bent markedly backward to Flüglrand out the second short, it flows away from the first in the wing edge. The transverse artery sc-r (between subcosta and radius) lies roughly in the middle of the wing, rr a little away from the wing tip. Four of the radial veins (five in the basic plan) lead into the wing edge (R2 is missing), R3 and R4 form a fork with a common trunk.

The abdomen of the winter mosquito is elongated, cylindrical. At the rear end of the male sit in a complex structure called hypopygic appendages transformed as mating organs, while the female has a curved ovipositor formed from two cerci . Their shape is often essential for determining the species.

Cold resistance

The winter mosquitoes are very insensitive to cold and can therefore be found especially in the winter months at altitudes of over 3000 meters. Scientific studies have shown that the body fluids of these frost-resistant mosquitoes contain glycerine- like substances. These act like antifreeze and prevent the mosquitoes from freezing through by tearing apart tissue and cells. Of all other frost-resistant insects, the winter mosquitoes are particularly characterized by the fact that they can develop activities at just above 0 ° C. In order to absorb even the slightest radiant heat in winter, their bodies have a dark gray color and their transparent wings also have almost black veins. The males of the animals form swarms of dancing , especially on sunny winter days and in early spring .

Larvae

The larvae of the winter mosquito have a fully developed head capsule, so they are eucephalic. They live mainly in the ground under leaf litter and feed on decayed plant remains. Some species also live in excrement and are coprophagous , such as some cave-dwelling species in the feces of bats . Only the foremost and the rearmost pair of stigmas are open for breathing , all others are closed by a stigma scar (amphipneustic). The pupae with short thoracic horns also live in the ground and work independently before the imago hatches to the surface.

Systematics

The winter mosquitoes are the sister taxon of the Tipuloidea and are placed together with these and the Triassic Gnomuscidae (only two species of a genus Gnomusca ) in the partial order Tipulomorpha , which in turn is the sister taxon of all other two-winged species.

The family is divided into two recent subfamilies, each comprising three genera:

Family Trichoceridae

  • Subfamily Trichocerinae
    • Trichocera Meigen, 1803. Holarctic . 109 species, mainly alpine and arctic. 89 species are known from the Palearctic, 52 of which are found in Europe.
    • Cladoneura Scudder, 1864 ( syn. Diazosma mountain Roth, 1913). holarctic. 5 types
    • Nothotrichocera Alexander, 1926. circum-Antarctic. 11 types
  • Paracladurinae Krzemińska subfamily, 1992
    • Paracladura Brunetti, 1911. South and Southeast Asia, Australis . 10 types
    • Asdura Krzemińska, 2006. Australis and Subantarctic. 4 types
    • Zedura Krzemińska, 2005. Australis and Subantarctic. 17 species

Central European species (selection)

Fossil evidence

The family is documented by fossil finds that go back to the Triassic. Numerous fossil genera and species have been described, which point to an earlier greater species richness. Especially in the Jura and in the Cretaceous, the winter mosquitoes, with 15 genera, were far richer in shape than recently. The genera Mailotrichocera , Rasnitsynina , Paleotrichocera , Kovaleva , Karatina , Eotrichocera , Tanychoreta , Zherikhinina and Undaya probably died out before the end of the Cretaceous (no fossil finds exist between the early Cretaceous and the Eocene). Fossils exist both as compression fossils in limestone and as amber inclusions, most of them from Mesozoic limestones from Central Asia.

Some specimens have been found in Baltic amber , at least two of which belong to the still existing genus Trichocera .

swell

  1. Dmitry Shcherbakov, Vladimir Blagoderov, Elena D Lukashevich (1995): Triassic Diptera and initial radiation of the order. International Journal of Dipterological Research 6: 75-114.
  2. David A. Grimaldi, Michael S. Engel: Evolution of the insects . Cambridge University Press, 2005, ISBN 0-521-82149-5 , pp. 496 .
  3. Ouafaa Driauach, Ewa Krzemińska, Boutaina Belqat: Genus Trichocera in Morocco: first records from Africa and a new species (Diptera: Trichoceridae). In: Zootaxa. 4059, 1, 2015, pp. 181-190.
  4. George O. Poinar Jr .: Life in Amber. Stanford University Press, Stanford (Cal.) 1992, ISBN 0-8047-2001-0 .
  5. Wolfgang Weitschat, Wilfried Wichard: Atlas of plants and animals in the Baltic amber. Pfeil-Verlag, Munich 1998, ISBN 3-931516-45-8 .

literature

  • Ewa Krzemińska, Wiesław Krzemiński, Christine Dahl: Monograph of fossil Trichoceridae (Diptera): Over 180 million years of evolution. Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Poland, 2009. ISBN 978-83-61358-20-6
  • CP Alexander: Trichoceridae. In: JF McAlpine et al. (Ed.): Manual of the nearctic Diptera. (= Research Branch Agricultural Canada Monograph 27). Vol 1, Hull 1981, ISBN 0-660-10731-7 , pp. 325-328.
  • K. Honomichl, H. Bellmann: Biology and ecology of the insects. + CD-Rom. Gustav Fischer Verlag, Stuttgart 1994.
  • Michael Chinery: Parey's Book of Insects. Franckh-Kosmos Verlag, Stuttgart 2004, ISBN 3-440-09969-5 .

Web links

Commons : Winter Mosquitoes (Trichoceridae)  - Collection of images, videos and audio files