Common crawfish
| Common crawfish | ||||||||||||
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Common crawfish ( Isophya kraussii ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Isophya kraussii | ||||||||||||
| Brunner von Wattenwyl , 1878 |
The common grasshopper ( Isophya kraussii ) is a species from the subfamily of the sickle horror (Phaneropterinae).
features
Since the species is the only representative of its genus in Central Europe, it can be determined there according to the genus characteristics. The animals are 16 to 26 millimeters long, with the females being slightly longer and having a much more plump physique. They have a green base color with numerous fine dark spots that are distributed on the body. Starting from the compound eyes , a light yellowish longitudinal line runs over the pronotum and along the edge of the wing, which is lined with a narrow red-brown inside in the rear section. The wings are reduced to scale-like lobes, the antennae are about one and a half times as long as the body. The cerci of the males are weakly basal, curved so strongly towards the tip that the tips point to one another. The laying tube ( ovipositor ) of the females is evenly curved upwards and only roughly toothed at the top and bottom.
The species is difficult to distinguish morphologically from other species of the genus Isophya . Species differentiation occurs mainly through the different mating songs of the males. Morphologically, the different singing corresponds to a different number of teeth on the serrated vein (called a file), which is used to generate sounds during stridulation . In the species there are around 260 to 305 teeth in the typical subspecies, 195 to 229 in the subspecies moldavica . The singing is soft, audible only a few meters away, and can only be heard at dusk, but only at temperatures above 15 ° C. It consists of a longer, soft clay in which a second, shorter and harder clay is embedded. This sounds a bit like repeating "ss-z". Most of the tones are in the ultrasonic range.
Occurrence
The species prefers bushy dry grassland , forest edges and tall, slightly damp meadows. It prefers clearly structured, tall, not too dry stands with tall grasses and herbs. In steppe-like habitats, it can only live on the edge of trees. The highest locations in southern Germany reach about 900 meters, in the Czech Republic up to 1800 meters. The adults appear early in the year from around mid-June, but the majority of the animals can be found from July. You can observe individual females until September.
The German deposits are in the low mountain range, mainly on the Swabian and Franconian Alb , east to the Middle Rhine Valley, north to the Harz. The species is noticeably absent in almost all areas south of the Danube, most of the old information from there is doubtful, it is completely absent in Switzerland. A large part of their distribution area is in Germany. Outside Germany, it occurs in eastern Austria (Lower Austria and Burgenland), in parts of the Czech Republic (with a few individual finds as far as southern Poland), western and northern Hungary, eastern Slovakia and occasionally in northern Croatia. The easternmost finds from north-east Romania (and probably also individual finds from Moldova and possibly dubious older finds in western Ukraine) are assigned to the subspecies moldavica .
Way of life
The phytophagous animals feed on soft and succulent plants. During mating, which lasts for one to two minutes, the male produces a very large spermatophore, the gelatinous shell of which the female eats for several hours so that the sperm can enter the sexual opening. The females lay their eggs in the ground in small groups.
Taxonomy and systematics
The genus Isophya comprises about 45 European species and is one of the most species-rich European leaf locust genera. For many decades, the Central European representatives of the genus Isophya were all assigned to the species Isophya pyrenaea (Serville, 1839), until Klaus-Gerhard Heller in 1988, comparing again with colleagues in 2004, showed that they cannot belong to this species described from southwestern Europe . They succeeded in distinguishing numerous new species, which had previously been misunderstood, mainly on the basis of bioacoustic (i.e. song) characteristics. For the Central European animals, they reinstated the old name Isophya kraussii , which until then had been regarded as a synonym, as a valid name. Today a subspecies is distinguished in addition to the nominate form.
- Isophya kraussii moldavica Iorgu & Heller, 2013. The main difference is the singing of the males. Described from the Moldavian region, Romania.
credentials
- Heiko Bellmann : Der Kosmos Heuschreckenführer, The species of Central Europe safely determine , Franckh-Kosmos Verlag GmbH & Co KG, Stuttgart 2006, ISBN 3-440-10447-8 .
- Jürgen Fischer, Daniela Steinlechner, Andreas Zehm, Dominik Poniatowski, Thomas Fartmann, Armin Beckmann, Christian Stettmer: The locusts of Germany and North Tyrol. Quelle & Meyer Verlag, Wiebelsheim 2016. ISBN 978-3-494-01670-2 .
- Ionuț Ștefan Iorgu, Klaus-Gerhard Heller (2013): The bush-cricket Isophya kraussii (Orthoptera: Phaneropteridae): bioacoustics, distribution and description of a new subspecies from Romania. Zootaxa 3640 (2): 258-269.
- K.-G. Brighter; KM Orci; G. Grein; S. Ingrisch (2004): The Isophya species of Central and Western Europe (Orthoptera: Tettigonioidea: Phaneropteridae). Tijdschrift voor Entomologie 147 (2): 237-258. doi: 10.1163 / 22119434-900000153
Web links
- Fauna Europaea: Taxonomy (English)
- Isophya kraussii at Orthoptera.ch
- DGfO German Society for Orthopterology e. V. Information on the species common grasshopper (Isophya kraussii)