Little thorn insect
| Little thorn insect | ||||||||||||
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Little thorn shrimp ( Aretaon asperrimus ), pair |
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| Scientific name | ||||||||||||
| Aretaon asperrimus | ||||||||||||
| ( Redtenbacher , 1906) |
The Small thorn cricket ( Aretaon asperrimus ) is a representative of the genus Aretaon from the order of the stick insects (Phasmatodea). The sometimes used term thorny ghost insect probably goes back to the common English name "Thorny Stick Insect". The species is also known as the spiny ghost insect or spiny ghost insect , but these names are not unique because they are also used for other spiny or thorny species. The term Borneo thorn stick insect which can also be found, is somewhat misleading, because the type is not the typical stick insects - habit corresponds to their occurrence and not on Borneo is limited.
features
Both sexes are completely wingless and have conspicuously thorns. Her eyes are mottled dark brown and yellow. On the head, the pro- and the metathorax there is a pair, on the mesothorax two pairs of spines are particularly well developed. These thorns are dark, red-brown, black-brown towards the tips. The rear pair on the mesothorax and that on the metathorax have even smaller side spines at their base. They stand out particularly clearly due to their contrast to the otherwise brown and beige marbled body of the female, or the male, which is drawn with yellow vertical stripes on a brown background. The legs, which are also brown, are also thorny. In addition to these normal-colored animals, very light-colored animals can also be found occasionally, in which the brown colors are lighter, sometimes light beige. As a result, the parts of the thorns that then appear wine-red are much more noticeable. In addition, the colors can fade significantly in the course of life, and older females in particular often appear as if they were covered with a layer of lime. In terms of habit , both sexes correspond to the sexual dimorphism typical of the subfamily Obriminae , in which the males , which are 50 to 60 millimeters in length, have a relatively slender abdomen with thicker end segments and the females, which are 80 to 90 millimeters in length, have a wider abdomen, which over time the oviposition swells significantly and ends in a sharp laying spine, the secondary ovipositor .
Distribution, behavior and reproduction
The small thorn insect is native to the Malay part of the islands of Borneo. Here it can be found especially in the north of the island, i.e. in the state of Sabah . It is also said to occur on Labuan and on the Philippine island of Luzon , more precisely in Benguet .
The nocturnal insects prefer to hide on or behind the bark of the food plants during the day. The males often allow themselves to be carried around by the females for days before, during and after mating. Four to five weeks after the last moult, the females begin to lay an average of one to a maximum of two cylindrical eggs a day with the laying stinger in the soil. These are 5.5 mm long, 2.5 mm high, 2.8 mm wide and about 25 mg in weight. They resemble the feces of their parents and have a micropylar plate in the shape of an upside-down Y. The ends of the lower legs of the micropylar plate reach the ventral side of the egg in about 40% of the eggs. Macroscopically , they can be differentiated from the eggs of the giant thorn insect ( Trachyaretaon carmelae ) by the leg of the micropylar plate that widens to the operculum . Depending on the temperature, the nymphs , which are already 18 mm long when hatched, usually hatch after 12 to 13 weeks, and rarely after four to five months. Adolescent nymphs have considerably more thorns to protect them from predators than adults. This is an adaptation that can also be found in other representatives of the subfamily Obriminae and takes into account the softer exoskeleton of the nymphs. Usually the adolescent nymphs have a lively beige to brown pattern. But animals with a green base color also appear.
Systematics and Etymology
The species was described by Josef Redtenbacher in 1906 under the name Obrimus asperrimus . In the same treatise he described another species as Obrimus muscosus on the basis of some very thorny 47 to 64 mm long nymphs. Both species were transferred to the newly established genus Aretaon by Rehn, JAG & Rehn, JWH in 1938/39 . The epithet "asperrimus" refers to the rough, prickly body surface ( Latin asper = rough, coarse; rimosus = cracked, full of crevices).
The syntypes of Aretaon asperrimus are kept in the Natural History Museum Vienna , in the Museo Nacional de Ciencias Naturales in Madrid and in the Zoological Museum of the Russian Academy of Sciences in St. Petersburg .
Terrariums
The small thorn insect was first introduced for terraristics in 1992 and a second time in 1996. Both strains come from the Kinabalu and were collected at a height of around 480 m. The Phasmid Study Group has them under PSG number 118.
Aretaon asperrimus is one of the easiest ghost horrors to care for. In addition to ivy , oak , hazelnut , red beech , wild roses , fire thorns and hawthorns , especially blackberries and other rose plants are eaten . The food plants are placed in the terrarium as leafy twigs in narrow-necked vases and sprayed with water about every two days (flower sprayer). To lay eggs, a five-centimeter-high layer of a slightly damp humus-sand mixture should cover the ground. The eggs can be left in the ground or transferred to a simple incubator for better control .
photos
Eggs
L1 nymph
female nymph
Image from Redtenbacher's original description
Web links
- www.phasmidsincyberspace.com - via Aretaon asperrimus
swell
- ^ A b Paul D. Brock , Thies H. Büscher & Edward W. Baker: Phasmida Species File Online . Version 5.0. (accessed on December 29, 2018)
- ↑ Dummy bull life
- ↑ a b Oliver Zompro : Basic knowledge of pasmids - biology - keeping - breeding . Sungaya Verlag, Berlin 2012, p. 69, ISBN 978-3-943592-00-9
- ↑ a b Christoph Seiler, Sven Bradler & Rainer Koch: Phasmids - care and breeding of ghosts, stick insects and walking leaves in the terrarium . bede, Ruhmannsfelden 2000, ISBN 3-933646-89-8
- ^ A b c Philip E. Bragg : Phasmids of Borneo , Natural History Publikations (Borneo) Sdn. Bhd., Kota Kinabalu, Sabah, Malaysia, 2001, pp. 103-109, ISBN 983-812-027-8
- ^ Rehn, JAG & Rehn, JWH : The Orthoptera of the Philippine Island, Part 1. - Phasmatidae; Obriminae , Proceedings of the Academy of Natural Sciences of Philadelphia, 90, 1938, p. 422
- ↑ Oliver Zompro: Locusts of the family Heteropterygidae in the terrarium - Reptilia - Terraristik Fachmagazin (No. 24, August / September 2000) Natur und Tier, Münster 2000
- ^ A b Roy Bäthe, Anke Bäthe & Mario Fuß: Phasmiden , Schüling Verlag, Münster 2009, ISBN 978-3-86523-073-7
- ↑ Oliver Zompro: Revision of the genera of the Areolatae, including the status of Timema and Agathemera (Insecta, Phasmatodea) . Goecke & Evers Verlag, Keltern, 2004, ISBN 3-931374-39-4
- ↑ Phasmid page by Frank H. Hennemann & Oskar V. Conle ( Memento of the original from May 2, 2011 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
