Crickets
| Crickets | ||||||||||||
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Crickets ( Acheta domesticus ) |
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| Scientific name | ||||||||||||
| Acheta domesticus | ||||||||||||
| ( Linnaeus , 1758) |
The house cricket ( Acheta domesticus ) is a long-feeler insect from the family of the real crickets (Gryllidae). The scientific name describes essential aspects of behavior and ecology: Acheta means 'singer' and domesticus 'domestic'. The house cricket is a very popular food insect in the terrarium hobby as well as a food insect .
features
Crickets are slightly smaller and slimmer than the field cricket ( Gryllus campestris ) and reach a body length of 16 to 20 millimeters, the ovipositor of the females measures an additional 11 to 15 millimeters. The body has a straw-yellow or yellow-brown basic color. The pronotum and head have dark brown to black markings.
There is no difference in the length of the fore wings between males and females. According to the measurement results in 30 adult males from one breed, the forewings are on average 10.55 millimeters long (extreme values: 9.1 to 12.3 millimeters) and do not cover the end section of the abdomen. In both sexes, the fore wings are slightly hardened and divided into a dorsal field and a lateral field. In the rest position, the dorsal fields of the two wings lie horizontally one above the other, that of the right wing is above that of the left wing. The lateral fields are perpendicular to the dorsal fields and cover the lateral parts of the abdomen.
The also fully developed hind wings are longer than the forewings and in females (mean: 18.92 millimeters) slightly longer than in males (mean: 17.12 millimeters). At rest, the hind wings are folded lengthways, their tips reach beyond the end of the abdomen. Crickets are able to fly, but they fly very rarely and only at high temperatures.
Stridulation apparatus
While the forewings of the females show a regular diamond pattern, the males have structures on the dorsal field with which species-typical noises are produced by stridulation, which are also known as chants.
The shrill veins, the shrill ledge with lamellae or shrill teeth and the shrill edge are involved in their formation, the harp and the mirror are involved in the reinforcement. The shrill loader first pulls backwards from the base of the wing, then bends in a sharp arc and runs to the inner edge of the wing. There is the thickened shrill edge in the immediate vicinity. The part of the shrill loader covered with shrill teeth is the shrill bar. In this section, the shrill teeth are arranged on the underside. They consist of a sturdy middle section with two pointed side extensions. The average number of shrill teeth on a shrill strip is 215.73 (extreme values: 193 to 260).
The part of the piano called the harp connects to the shrill loader. It is characterized by some oblique to wavy veins. This is followed by the mirror, an approximately round part of the dorsal field delimited by a vein with an arched central vein. The rear section of the dorsal field (apical field) has a network of small veins. All these structures are formed in the same way on both wings.
Occurrence
The species was originally probably only distributed in the arid and semi-arid parts of Africa. Today it occurs all over the world, in East Africa it has been detected at altitudes of over 2,600 meters. In cool areas such as Central Europe, the crickets occur particularly in or near human settlements ( synanthropy ), as otherwise they cannot survive the winter. They prefer habitats with high humidity, such as cellars, greenhouses or even damp underground shafts. Compost stores are ideal habitats, as the fermentation of the waste causes high temperatures all year round.
Way of life
Crickets are light-shy and nocturnal. During the day they hide, but are occasionally active in the shade. They are omnivores , feed on plant and animal foods, but prefer the latter. Since they primarily meet their water needs through food, they like to consume water-based food. They also feed on food, waste, and carrion. In the case of massive numbers, they are satisfied with inferior food. Cannibalism also occurs. Crickets are easy to breed. With enough warmth and sufficient food consisting of, for example, lettuce, carrots and oatmeal, the adult crickets reproduce without problems and the larvae of all stages develop quickly.
Reproduction and development
Male crickets ready to mate chirp from dusk until late at night. They express normal or ordinary singing. This is strong and monotonous. Compared to the similar sounding chant of the field cricket, however, it is more irregular in the number and length of the syllables and the intervals between them. The dominant frequency is 3800 Hertz.
When chirping, the males erect their forewings, spread them outwards (picture) and then move them inwards and outwards against each other. The shrill teeth of the right wing brush over the shrill edge of the left wing. The sound utterances arise during the inward movements of the wings.
Females ready to mate migrate to the chirping males. After touching the antennas, the males move on to commercial singing. This is followed by mating, in which the males each transfer a spermatophore with the sperm it contains to the females.
The females lay their first eggs two to three days after mating. This is done individually or in groups in moist soil or in vegetable scraps, sawdust and similar substrates. The eggs are 0.3 by 2.3 to 2.5 millimeters long and curved. Depending on the diet of the female, around 1,100 eggs are laid on a vegetable diet and around 2,600 eggs on a animal diet. The eggs are insensitive to moisture and also absorb it, so that they swell to about twice the weight. Depending on the temperature, the larvae hatch after about 8.5 (at 35 ° C) to 54 (at 16 ° C) days. They are initially about 2.3 millimeters long and colored dark gray. In 87 to 126 days, depending on the temperature and the food found, 9 to 16 larval stages are passed through until the animals molt into an imago .
Hazard and protection
The cricket is widespread in Central Europe and safe as a cultural follower .
Crickets as food
Crickets are used as food insects all over the world , especially in Asia. In Europe, too, house crickets are used for various novel, processed foods such as fitness bars, insect noodles, burger patties or insect bread, mostly in ground form (cricket meal). In Switzerland , house crickets (Acheta domesticus) have been permitted as food since May 1, 2017. Under certain conditions, these can be given to consumers as whole animals, shredded or ground.
Crickets in music and literature
The novella Das Heimchen am Herd , one of the five Christmas stories by Charles Dickens, is about the little house as a lucky charm .
In the poem “Conquistadores” by Conrad Ferdinand Meyer, the cabin boy's cricket shows the proximity of America (“The cricket chirps”).
In the lullaby "Die Blümelein they sleep" by Wilhelm v. Zuccalmaglio finds it mentioned in the second stanza: "... the cricket in the ground of corn, it alone makes itself known ...".
The poet in Franz Schubert's art song “Der Einsame” (D 800, Op. 41, lyricist: Karl Gottlieb Lappe ) also sings about the crickets as a welcome company and musicians at the evening hour by the warm stove.
Web links
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.
- Max Beier, Franz Heikertinger: Grilling and mole crickets . The new Brehm library. A. Ziemsen Verlag, Wittenberg Lutherstadt 1954, pp. 1-35.
- Hans Schneider: Crickets and grasshoppers: vocal insects in our homeland. Spessart 105, pp. 3–9, 2011.
supporting documents
- ↑ 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.
- ↑ Heiko Bellmann : Der Kosmos Heuschreckenführer, Determine the types of Central Europe safely , Franckh-Kosmos Verlag-GmbH & Co KG, Stuttgart 2006, ISBN 3-440-10447-8 .
- ↑ Max Beier, Franz Heikertinger: Grilling and Mole Crickets . The new Brehm library. A. Ziemsen Verlag, Wittenberg Lutherstadt 1954, pp. 1-35.
- ↑ Hans Schneider: Crickets and grasshoppers: Insects gifted with voice in our homeland. Spessart 105, pp. 3–9, 2011.
- ↑ Deutschlandfunk Kultur / Volker Mrasek (December 30, 2017): Insects as food - Fried maggots for dessert .
- ↑ Deutschlandfunk Kultur / Daniela Siebert (August 14, 2018): Crickets and worms as food - insect burgers made from beetle larvae .
- ↑ Hannoversche Allgemeine (November 23, 2017): Stulle mit Grille: Finns test insect bread .
- ^ FSVO (April 28, 2017): Insects as food .
- ↑ Charles Dickens: Christmas stories in the Gutenberg project .
- ^ Conrad Ferdinand Meyer: Conquistadores in the Gutenberg project.
- ^ Wilhelm v. Zuccalmaglio: The little flowers they sleep on the website Singen undpiele.de .
- ↑ Karl Gottlieb Lappe: Text to Schubert's song Der Einsame on Schubertlied.de.