Marsh grasshopper

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Marsh grasshopper
Male marsh grasshopper (Chorthippus montanus)

Male marsh grasshopper ( Chorthippus montanus )

Systematics
Order : Grasshoppers (Orthoptera)
Subordination : Short-antennae terrors (Caelifera)
Family : Field locusts (Acrididae)
Subfamily : Grasshopper (Gomphocerinae)
Genre : Chorthippus
Type : Marsh grasshopper
Scientific name
Chorthippus montanus
( Charpentier , 1825)
Female marsh grasshopper

The marsh grasshopper ( Chorthippus montanus ) is a short-antennae insect from the family of field locusts (Acrididae). It is very similar to the common grasshopper ( Chorthippus parallelus ), which is why both species were previously summarized as Chorthippus longicornis . The common and marsh grasshopper also hybridize occasionally in nature. The species is common in large parts of Europe and Asia. The swamp grasshopper colonizes permanently moist to wet habitats with a maximum of medium-high vegetation. In Germany, Austria and Switzerland, it is particularly threatened by the destruction of its habitat or changes in its use.

features

The animals reach a body length of 12.9 to 16.0 millimeters (males) or 17.0 to 22.0 millimeters (females). As with most grasshoppers (Gomphocerinae), their coloring is variable. Often green morphs with brown backs and pure green morphs occur. The swamp grasshopper and the common grasshopper differ from the other species of the genus Chorthippus by their dark knees, shortened wings and only slightly curved pronotum side keels. The two species are difficult to distinguish from each other. The body of the swamp grasshopper is slightly stronger and the wing patch, which is at least 2.5 millimeters away from the wing tip, is weaker in this species, making the cover wings appear more transparent. In the males of the marsh grasshopper, the hind wings (alae) reach up to just in front of the wing spot or directly to it. The fore wings (Elytren) are longer than in the similar species and reach at least to the middle of the hind legs. They are 9 to 11.8 millimeters long in the males and 14.5 to 18 millimeters long in macroplastic animals. In females they measure 8.7 to 12 or 14 to 18 millimeters. The alae are always shorter than the elytra when they are folded up. They are either half as long as it or tower above it. In males they are usually 5 to 7 millimeters long, in females 5 to 6 millimeters. The pronotum is 2.6 to 3.4 millimeters long in the males and 3.3 to 4.3 millimeters long in the females. The shrill ridge has an average of 137 to 139 cones, in the case of the common grasshopper it is only 94. The females of the marsh grasshopper can be distinguished from those of the similar species by the longer laying tube flaps, and their wing tips are more rounded. In both types, long-winged, fully airworthy forms also occur in both sexes.

Occurrence

The species is common in Europe and Asia. It occurs from Western Europe to the Kamchatka Peninsula on the Pacific. In Europe, the northern limit of distribution runs through northern France, the Benelux countries and northern Scandinavia . In Finland the distribution up to latitude 68 ° north has been documented. To the south, the border runs from the Pyrenees over the French Massif Central , the southern edge of the Central Alps, the Apennines to the northern part of the Balkan Peninsula and over Romania to Mongolia and Manchuria . The species is widespread in Central and Eastern Europe, even at low altitudes. It occurs in the Alps between 370 and 2480 meters above sea level, but prefers the colline and montane levels. In Asia, the distribution extends from southern Siberia north to Verkhoyansk , the Altai and Kamchatka.

The marsh grasshopper is extremely moisture-loving and inhabits moist to wet habitats with a maximum of medium-high vegetation such as wet meadows, swampy areas on lake shores and rivers, high and fens. High-growing areas such as fallow land, sedge reeds or reed beds are not populated. The species often occurs in company with the long-winged sword insect ( Conocephalus fuscus ), the marsh insect ( Stethophyma grossum ) and the meadow grasshopper ( Chorthippus dorsatus ). The common grasshopper ( Chorthippus parallelus ), with which the swamp grasshopper can also hybridize locally, is often found in the adjacent drier habitats .

Way of life

The marsh grasshopper's way of life is similar to that of the common grasshopper. The animals feed on blue pipegrass ( Molinia caerulea ), reed ( Phragmites australis ), black headgrass ( Schoenus nigricans ) and various sour grasses . Under laboratory conditions, mainly sweet grasses and only a few sour grasses such as sedges ( Carex ) are eaten.

Adult animals can be observed from June to November, exceptionally even at the end of May. They appear about a month later than those of the common grasshopper. The marsh grasshopper is one of the latest to hatch short-antennae terrors in Central Europe. At the beginning of September the maximum population size of adult individuals is reached.

pairing

The song of the marsh grasshopper is performed much more slowly than that of the common grasshopper, but is otherwise very similar. In general, the marsh grasshopper's singing sounds coarser and louder. As with the common grasshopper, it slows down in colder temperatures, which makes it difficult to differentiate between the two species in changeable weather. Occasionally one can hear alternating chants between males of both species. The females can sing almost as loudly as the males, but rarely respond to males. The individual verses of the chant consist of 2 to 4.5 seconds in a row, "schr-schr-schr" sounds, followed by a pause of four to seven seconds. A verse comprises about 12 to 22 syllables. The singing of rival males is slower.

If females are unwilling to mate, they do not approach the singing males and make defensive movements with their hind legs when the males attempt to mate. Females ready to mate approach the male, answer him or are found by him by chance. Males are ready to mate with the adult approximately 4 to 12 days after molting and can also mate several times a day. This means that they can produce the spermatophore and the sperm it contains relatively quickly. The pairing takes an average of 26 minutes.

development

The females lay six to seven cocoons with about seven eggs each. Compared to related species of the genus Chorthippus , they lay only a third to half as many eggs. These are not very tolerant of drought. If there is insufficient moisture during embryonic development, the nymphs will not grow as large and their death rate will be higher. The females lay their eggs either in the soil or in the root felt of sedges . In contrast to the common grasshopper, the females of the marsh grasshopper do not make scratching movements with their hind legs. The development to hatching is slower than that of other species due to the low temperatures of their habitats. The nymphs, on the other hand, develop relatively quickly. A total of five nymph stages are experienced.

Hazard and protection

The species is listed in the Red List of Threatened Species in Germany on the warning list, in the Swiss Red List it is listed as "Vulnerable" (VU), in the Austrian Red List it is listed as "Endangered" (NT). The main reason for the endangerment of the species is the loss of habitat due to water grading, drainage, lowering of the groundwater and the like. Particularly through agriculture, suitable wetlands are drained and thus destroyed. The afforestation and fallowing of wetlands and fen meadows also destroy the livelihoods of the species. As a result, there is also an increasing risk of population isolation.

The continued existence of moist meadows, swamps and moors are important for the conservation of the species. Raising the water table in river valleys to a natural level can also help. The maintenance of moist meadows can be done by mowing once or twice a year or by extensive grazing.

Systematics and taxonomy

The species was in 1825 by Charpentier in his work Horae entomologicae adjectis tabulis novem coloratis as " Gryllus montanus " first described . As was customary at the time, he did not give a holotype . An individual from the collection of the Entomological Museum of the Zoological Institute of Lund University was later identified as a neotype . Type locality is Saxony and Silesia. Due to its strong resemblance to the common grasshopper ( Chorthippus parallelus ), the species was previously summarized as Chorthippus longicornis . The species status was often questioned in the 19th century, until Faber (1929) carried out a detailed study of the morphology and in particular of the chants and separated the two species Chorthippus parallelus and Chorthippus montanus . The epithet indicates its occurrence at higher altitudes, but this only applies in the south of the distribution area.

supporting documents

literature

  • Bertrand & Hannes Baur, Christian & Daniel Roesti: The locusts of Switzerland . Haupt Verlag, Bern 2006, ISBN 3-258-07053-9 .
  • Heiko Bellmann : The Cosmos Locust Leader. Determine the species of Central Europe with certainty . Franckh-Kosmos, Stuttgart 2006, ISBN 3-440-10447-8 .
  • Peter Detzel: The locusts of Baden-Württemberg . Eugen Ulmer, Stuttgart 1998, ISBN 3-8001-3507-8 .

Individual evidence

  1. ↑ a b c d e K. resin: . The Orthoptera Europe II Dr. W. Junk BV, The Hague 1975.
  2. ↑ a b Hochkirch A. & Lemke I. (2011): Asymmetric mate choice and hybrid fitness in two sympatric grasshopper species. In: Behavioral Ecology and Sociobiology Volume 65, Number 8, pp. 1637-1645. doi : 10.1007 / s00265-011-1174-6
  3. ↑ a b c d e f g h i j k l m n o Peter Detzel: The locusts of Baden-Württemberg . Eugen Ulmer, Stuttgart 1998, ISBN 3-8001-3507-8 , pp. 513 ff .
  4. ↑ a b c d e f g h i Bertrand & Hannes Baur, Christian & Daniel Roesti: The locusts of Switzerland . Haupt Verlag, Bern 2006, ISBN 3-258-07053-9 , p. 336 .
  5. ^ Bertrand & Hannes Baur, Christian & Daniel Roesti: The locusts of Switzerland . Haupt Verlag, Bern 2006, ISBN 3-258-07053-9 , p. 309 ff .
  6. ↑ a b c d Heiko Bellmann : The cosmos locust leader. Determine the species of Central Europe with certainty . Franckh-Kosmos, Stuttgart 2006, ISBN 3-440-10447-8 , pp. 332 .
  7. ^ Reynolds WJ: A reexamination of the characters separating Chorthippus montanus and Chorthippus parallelus (Orthoptera, Acrididae). In: Journal of Natural History 14 , 1980, pp. 283-303
  8. ↑ T. Kaufmann: Biological studies on some bavarian Acridoidea (Orthoptera), with special reference to their feeding habits . Annals Entomol. Soc. America 58 (6): P. 791-801 in Peter Detzel: Die Heuschrecken Baden-Württemberg . Eugen Ulmer, Stuttgart 1998, ISBN 3-8001-3507-8 .
  9. ^ A b Weyer J., Weinberger J. & A. Hochkirch (2012): Mobility and microhabitat utilization in a flightless wetland grasshopper, Chorthippus montanus (Charpentier, 1825). In: Journal of Insect Conservation. Volume 16, Number 3, 2012, pp. 379–390 doi : 10.1007 / s10841-011-9423-6
  10. ^ Ragge DR, Reynolds WJ (1998): The songs of the grasshoppers and crickets of Western Europe. Harley Books, London
  11. ↑ S. Maas, P. Detzel, A. Staudt (2011): Red list and total species list of grasshoppers (Saltatoria) in Germany In: M. Binot-Hafke et al. (Editor): Red List of Endangered Animals, Plants and Fungi in Germany. Volume 3: Invertebrates (Part 1) - Federal Agency for Nature Conservation (Ed.), Nature Conservation and Biological Diversity 70 (3): pp. 577–606
  12. ^ Christian Monnerat, Philippe Thorens, Thomas Walter, Yves Gonseth: Rote Liste Heuschrecken. Red list of endangered species in Switzerland Federal Office for the Environment and Swiss Center for the Cartography of Fauna, Bern 2007.
  13. ↑ K. Adlbauer, A. Kaltenbach: Red list of endangered grasshoppers and crickets, catchy tunes , cockroaches and catching horrors. (Saltatoria, Dermaptera, Blattodea, Mantodea) in: J. Gepp (Red.): Red Lists of Endangered Animals Austria (= Green Series of the Federal Ministry for the Environment, Youth and Family, Vol. 2 ). Vienna 1994.
  14. ↑ Faber A (1929) Chorthippus longicornis Latr. (= parallelus Zett.) and Chorthippus montanus Charp. (previously called "longicornis Latr." according to Finot). Zoological Bulletin 81: 1-24

Web links

Commons : Chorthippus montanus  - Collection of images, videos and audio files
This version was added to the list of articles worth reading on May 31, 2012 .