Roesel's bite
| Roesel's bite | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Roesel's Bite Insect ( Roeseliana roeselii ), male |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Roeseliana roeselii | ||||||||||||
| Hagenbach , 1822 |
Roesel's bite insect ( Roeseliana roeselii ) is a long- feeler insect from the superfamily of leaf locusts (Tettigonioidea). It is one of the most common and widespread species of grasshopper in Central Europe. It is named after August Johann Rösel von Rosenhof , who, with his famous "insect amusements", paved the way for scientific observation of nature.
features
The animals reach a body length of 14 to 19 millimeters. The males are smaller than the females, while the forewings of the males are longer (mean: 8.35 millimeters; extreme values: 7.2–10.0; 40 males) than of the females (mean: 6.09 millimeters; extreme values : 4.5-8.2; 10 females). The fore wings are broad in their entire length. The hind wings are very short in both sexes. The mean values are 2.87 millimeters for the males and 3.02 millimeters for the females. The difference lies in the random area. The body has a green-olive, brown, red-brown or light brown basic color. The lateral lobes of the pronotum are broadly bordered yellowish white to light green. The thighs ( femora ) of the hind legs have a black horizontal line on the outside, above which the thighs are greenish to yellowish in color. The cerci of the males have a long, inward spine at the beginning of the apical third. The subgenital plate of the female is deeply incised; their ovipositor is 7 to 8 millimeters long. The wings are brownish in color and usually only reach about half the length of the abdomen. In some individuals, however, they extend to the end of the abdomen or even rise above it.
Occurrence
The species occurs in Europe and Asia . The distribution extends from eastern Spain over large parts of western, central, southern and eastern Europe to the Middle East and Siberia . To the north, the distribution area extends to Ireland , to the south of England , Denmark , to the south of Sweden and Finland . It can be found from the lowlands to locations around 1,000 meters, above which the species is rare. On the north side of the Alps and in Vinschgau it has been proven up to 1800 and 1500 meters respectively. They prefer to live in fresh, natural meadows, but the species can be found in both dry and damp grasslands and on fertilized meadows.
Some authors describe the populations occurring in southern, southeastern Europe and Asia as separate species, different from R. roeselii . These populations differ morphologically from the other individuals and show similarities to Roeseliana fedtschenkoi , but they have the same song as R. roeselii . However, it is assumed that these animals are also the species R. roeselii .
Way of life
Roesel's bite is active during the day, and you can occasionally hear its singing at night. It feeds mainly on grasses; herbaceous plants and smaller insects as well as conspecifics are only eaten occasionally. The grasses are scraped off on the surfaces and not consumed as a whole. The females lay their eggs 4.5 to 4.8 millimeters long and about one millimeter wide, individually or in small groups, in marrow-rich, fresh and dry stems of various grasses, herbaceous plants and shrubs. To do this, a hole is first gnawed into the stem, into which the ovipositor is then inserted. The larvae hatch in spring around the end of May, but depending on the environmental conditions, they can sometimes survive for a year. The animals go through seven stages in about 40 days until they are fully grown. The adults are found from late June to late October. They are relatively insensitive to the cold and can also survive light night frosts undamaged.
Stridulation organ
On the left fore wing of the males, the shrill vein and its parts are well developed (picture), with an average of 2.45 millimeters. The shrill bar as a section is 1.3 millimeters long and has an average of 70.38 shrill teeth on the underside. The shrill tooth density on the left shrill bar is 42.18 shrill teeth / millimeter and is possibly only surpassed by the cricket ( Acheta domesticus ), in which the density is 54.14 shrill teeth / millimeter. The high- pitched buzzing of the song in Roeseliana roeselii is possibly due to the high density of the shrill teeth. The outline of the mirror can still be seen on the left wing, albeit only indistinctly. On the right front wing, on the other hand, the mirror is fully designed as a resonator and clearly delimited by a chitin frame (picture). It is noticeable that it is thickened and heavily pigmented on one side. The shrill charger is still present in a reduced form on the right wing. On average it measures only 1.89 millimeters, the shrill bar only 0.85 millimeters, the number of shrill teeth is 42.18 on average. The locusts examined come from the area around Töging am Inn in Upper Bavaria.
Courtship and mating
The males advertise with a soft, buzzing song that can be heard about 10 meters away. This comprises about 75 syllables per second and is even, long-lasting and is only interrupted by short pauses. Closing the wings creates a loud half-syllable and opening it a soft half-syllable. The former has a frequency of 20 to 25 kHz , the second from 30 to 40 kHz.
Stridulating Roesel's bite insect
swell
Individual evidence
- ↑ a b Anna Alfonsa Stark: Investigations on the sound organ of some crickets and grasshopper species, at the same time a contribution to the right-left problem. Zoological Yearbooks, Department of Anatomy and Ontogeny of Animals 77, pp. 9–50, 1958.
literature
- 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 .
- Peter Detzel: The locusts of Baden-Württemberg. Verlag Eugen Ulmer GmbH & Co, Stuttgart 1998, ISBN 3-8001-3507-8 .
- Anna Alfonsa Stark: Investigations on the sound organ of some crickets and grasshopper species, at the same time a contribution to the right-left problem. Zoological Yearbooks, Department of Anatomy and Ontogeny of Animals 77, pp. 9–50, 1958.
