Hair gnats
| Hair gnats | ||||||||||||
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March flies ( Bibio marci ) mating (left male, right female) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Bibionidae | ||||||||||||
| Fleming , 1821 | ||||||||||||
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The hair gnats (Bibionidae) are a family of the two-winged birds (Diptera) and belong to the mosquitoes (Nematocera). Around 700 species of this group of animals live worldwide, around 50 of which are known from Europe. In addition, there are 344 described fossil species. They are medium-sized mosquitoes.
features
The hair mosquitoes are very hairy and dark mosquitoes that look almost like flies . As a classic mosquito characteristic, however, the long and evenly structured antennae are noticeable (2 basal segments with a subsequent multi-segmented flagella), which are relatively short and stocky for mosquito representatives. The males have very large compound eyes , the upper part of which consists of large, the lower part of small individual eyes . The eyes meet on the top of the head and are hairy. This type of eye obviously enables a stabilization of the flight in the horizontal plane. In the females, the eyes are much smaller, uniformly faceted and hairless. The females also have a burrowing thorn on their front legs (more precisely on the tibia ). In many species, the sexes also differ in color, the males are black and the females are red to yellow-brown.
Way of life
The hair gnats occur in large swarms, especially in spring, sometimes also in autumn. They are mostly good fliers, but the garden hair mosquito ( Bibio hortulanus ) is quite sluggish and not particularly nimble on foot. They do not sting and are of no insignificant importance in the pollination of early-flowering fruit trees. They feed on nectar and honeydew . The March fly , or St. Mark's fly ( Bibio marci ) usually sits in bushes. It is named after St. Mark because it occurs particularly frequently around his feast day ( April 25 ).
To mate, the partners are found in the swarms, copulation usually begins in the air and ends on the ground. The males of the March fly fly at all flying objects that are depicted in the upper part of the eye and attack them. If it is a female, it is taken for mating. The eggs are laid in humus-rich soil, the scent of humus probably causing the discovery. The eggs are buried in the ground individually or in small clutches, with each female able to lay up to 3,000 eggs.
Larval development
The young larvae are often very hairy, the later stages have spiny appendages that can vary in length. The tracheal system has ten pairs of open spiracles . The larvae are often found in clusters, with enormous masses sometimes occurring in the upper humus layers, especially in the forest under fallen leaves or in the vicinity of dead wood and tree stumps. They live on rotting plant parts and are important humus formers ( saprophages ). In the case of mass occurrences, possibly also in drought, the larvae also attack the roots of living plants and can thus become harmful, especially after overwintering (always as a larva, in the case of the locust hair mosquito ( Bibio johannis ) around the second larval stage). The larvae are quite insensitive to cold. The doll has only very short breathing horns and lives in the ground. The hair mosquitoes usually only have one generation a year, while the radiation mosquito Dilophus febrilis , which is important as a pollinator of fruit trees, has two generations.
Genera
The three species of hair gnats found in Europe, Penthetria , Dilophus and Bibio, differ in terms of the occurrence of burial thorns at the distal end of the tibia :
- Tibia without terminal mandrel: Penthetria Meigen
- Tibia of the forelegs with a wreath of thorns: Dilophus Meigen
- Tibia of the forelegs with a strong terminal mandrel: Bibio Geoffroy
Fossil evidence
Strongly crushed specimens of members of this family are known from the Upper Triassic of North America (Dan River Formation). The oldest fossil evidence of a completely preserved hair mosquito comes from Canadian amber from the Cretaceous period . It is the species Plecia myersi. Further finds from the Mesozoic Era come from a deposit in the Lower Jura in Germany, from Siberian amber and Cretaceous deposits in Central Africa, South America and Scotland. The family has also been identified with several genera from various tertiary deposits (e.g. from Baltic amber , Mexican amber and Dominican amber ).
Individual evidence
- ↑ Bibionidae at Fauna Europaea
- ↑ http://hbs.bishopmuseum.org/fossilcat/fossbibio.html fossil Diptera
- ^ BV Peterson: A new Cretaceous bibionid from Canadian Amber (Diptera: Bibinoidae) . In Canadian Entoml. 107, cited in Poinar 1992.
- ↑ George O. Poinar, Jr .: Life in Amber. Stanford University Press, Stanford CA 1992, ISBN 0-8047-2001-0 .
- ↑ John Skartveit: Fossil Hesperinidae and Bibionidae from Baltic amber (Diptera: Bibionoidea). In: Studia dipterologica . tape 15 , issue 1/2, 2008, ISSN 0945-3954 , p. 3-42 .
literature
- P. Freeman, RP Lane: Bibionid and Scatopsid flies. Diptera: Bibionidae and Scatopsidae. In: Handb Ident British Insects. 9 (1985) (7). London
- Willi Hennig : Diptera, two-winged one. In: Handbook of Plant Diseases. V (2), 1st edition, 5th edition. Hamburg / Berlin 1953.
- K. Honomichl, H. Bellmann: Biology and ecology of the insects. CD-ROM. Gustav Fischer Verlag, Stuttgart 1996, ISBN 3-437-25020-5 .
- L. Papp, B. Darvas (Ed.): Contributions to a Manual of Palaearctic Diptera (with special reference to flies of economic importance). In: Nematocera and Lower Brachycera. 2 (1997); Science Herald, Budapest, pp. 1-592.
- W. Schwenke: Bibionidae. In: The forest pests of Central Europe. Vol. 4, Hamburg 1982.
- P. Seifert, H. Wunderer, G. Weber: Can the ocelles contribute to flight stabilization in bibioid males? An assessment of their particular morphology. In: Verh Dtsch Zool Ges. 8 (1988), p. 302.
