Steppe cricket

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Steppe cricket
Female steppe cricket (Gryllus assimilis)

Female steppe cricket ( Gryllus assimilis )

Systematics
Class : Insects (Insecta)
Order : Grasshoppers (Orthoptera)
Subordination : Long- probe horror (Ensifera)
Family : Real crickets (Gryllidae)
Genre : Gryllus
Type : Steppe cricket
Scientific name
Gryllus assimilis
( Fabricius , 1775)

The steppe cricket ( Gryllus assimilis ) is a long-feeler insect from the family of the real crickets (Gryllidae).

In terraristics , food insects traded under this name are often used as live food. In fact, however, these often belong to a different species, which was only newly described in 2012, of which no natural occurrence is known to date. In addition, the steppe cricket is EU-wide approved for feed in aquaculture .

features

A - singing male, B - female, C - newly hatched young, D / E - females laying eggs

The steppe cricket is similar to the cricket ( Acheta domesticus ), but is significantly larger. The females grow up to 35 mm, males below that. The basic color is often yellowish-brown, only the abdomen and the front of the head are black; in fact, however, different individuals can have all color variations from reddish to completely black. The head is always narrower than the pronotum. The skinning seam on the front of the head is distinctly inverted Y-shaped, the region around the eyes is light yellowish-brown. The pronotum is densely hairy, which is why the animal does not shine, but the hairiness is individually variable. The species is long-winged (macropter) and capable of flight, the wings are the same length in adults of both sexes. It seldom happens that animals shear off the hind wings mechanically. The stridulation apparatus of the males has 94 to 125 teeth.

Occurrence

The natural range of the steppe cricket includes the West Indies as well as parts of Mexico and a small area in the adjacent Texas to the north . The type locality is Jamaica , where three species of crickets live. The species has only appeared in south Florida since the middle of the 20th century. The species occurs mainly in open areas such as meadows, fields and on the edges of roads and reproduces year-round.

Utterance

The call of the steppe cricket consists of a short chirp that is repeated about every second. Each chirp consists of seven or more impulses that follow each other at a high frequency (~ 90 / s) and thus result in an almost continuous sound impression. The frequency of the impulses is around 4 kHz.

Systematics

In 1915, Behn and Hebbard synonymized all American cricket species described up to then under the Latin name Gryllus assimilis . This broad collective type was only dissolved again in 1957. By analyzing the male mating chants in particular, in connection with DNA analysis, a whole series of new species have been described, which Gryllus assimilis s. st. are difficult to distinguish morphologically. The species in the modern delimitation is based on the revision of Weissman et al. 2009.

Use as a feed insect

Commercial cricket breeding, especially as feed insects for terraristics, is an important industry in many countries today. In the US alone, more than 50 million crickets are shipped each week. Since the most popular species, the house cricket ( Acheta domesticus ), which was severely decimated by a virus epidemic, which caused many breeders to go bankrupt, Gryllus species have been increasingly traded. In addition to the European Gryllus bimaculatus , the East Asian Gryllodes sigillatus and animals sold under the trade name " Gryllus bimaculatus " are commercially significant . According to a more recent investigation, however, it turned out that it is not always, and none of the examined European breeds, actually is this species. The newly recognized and described, very similar cultivar was named Gryllus locorojo Weissman and Gray, 2012. Due to the DNA sequence and the song, which is similar to Gryllus argentinus , there is speculation about a South American origin. The animals have been bred in Europe for decades and were apparently only recently exported from there to the USA. Both species are infected by the cricket virus (Acheta domesticus densovirus, AdDNV), which is less lethal in them.

swell

Individual evidence

  1. ↑ a b c David B. Weissman, David A. Gray, Hanh Thi Pham, Peter Tijssen (2012): Billions and billions sold: Pet-feeder crickets (Orthoptera: Gryllidae), commercial cricket farms, an epizootic densovirus, and government regulations make for a potential disaster. Zootaxa 3504: 67-88.
  2. ^ A b David B. Weissman, Thomas J. Walker, David A. Gray (2009): The Field Cricket Gryllus assimilis and Two New Sister Species (Orthoptera: Gryllidae). Annals of the Entomological Society of America Vol. 102, no. 3: 367-380.
  3. ↑ J. Szelei, J. Woodring, MS Goettel, G. Duke, F.-X. Jousset, KY Liu, Z. Zadori, Y. Li, E. Styer, DG Boucias, RG Kleespies, M. Bergoin, P. Tijssen (2011): Susceptibility of North-American and European crickets to Acheta domesticus densovirus (AdDNV) and associated epizootics. Journal of Invertebrate Pathology, Volume 106, Issue 3: 394-399. doi : 10.1016 / j.jip.2010.12.009

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