Madagascar hissing cockroach
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Madagascar hissing cockroach ( Gromphadorhina portentosa ) |
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| Gromphadorhina portentosa | ||||||||||||
| ( Foam , 1853) |
The Madagascar hissing cockroach ( Gromphadorhina portentosa ) is a cockroach from the Blaberidae family . The species is often kept in terrariums, it is a widely used experimental animal for ethological and developmental studies.
features
It is a large species of cockroach with a body length between 45 and 88 millimeters. The flattened, wingless animals are from reddish brown to dark brown to black in color. The pronotum is rounded, trapezoidal, its front edge covers the slightly drooping head when viewed from above. Typical of the genus, in addition to numerous tubercles, are two bulbous to horn-like outgrowths on the pronotum, between which a depression of roughly rectangular shape is visible. They are much less pronounced in the females than in the males. In the species there is a small, secondary tubercle in the posterior half of these outgrowths, which is best seen in profile.
The species are difficult to distinguish from each other and from the representatives of the similar genus Elliptorhina . According to the species descriptions, many of the animals kept in terrariums actually belong to other species.
habitat
The distribution area of the Madagascar hissing cockroach is Madagascar , where it lives in the dry thorn forest that is characteristic of the island , up to semi-evergreen rainforests. Almost nothing is known about the species in the natural habitat, information on the way of life is largely based on animals kept in terrariums. The few finds in the field are mostly found either in rotten wood or in the leaf sheaths of dead leaves on living plants.
nutrition
The Madagascar hissed cockroach is an omnivore , which means that it basically eats everything: vegetables, meat, fruit and fruit, and also the leaves and bark of branches. Like most cockroaches, they are able to consume around half their body weight in one feeding process. Even skins deposited after the growth moults are eaten.
Way of life
The cockroaches reach an age of a good three years. They reach sexual maturity at five months. The sexes can be easily distinguished. Males have two easily recognizable humps on the pronotum. At a temperature of 25–30 ° C and a relative humidity of 40–70%, the first pairings should soon be observed. The females hide the ootheca (egg packet) inside the body after first turning it out and then pulling it in again. The ootheca is carried around until the young nymphs hatch ( ovoviviparia ). The 30-40 young nymphs leave the ootheca after 50-60 days, they are then about 3.5 to 5 millimeters long and initially colored white. Seven to eight nymph stages are passed through, generally one less in the males than in the females. The development to sexual maturity takes about 6 to 9 months.
This species is characterized by the hissing sound it emits by expelling air through a pair of modified stigmas . All animals hiss when they feel threatened, and males also hiss to deter rivals, during mating foreplay and copulation.
attitude
The species is usually kept and bred in simple glass or plastic terrariums . A stable cover must be ensured when keeping the animals, as the animals can easily run up smooth panes. The bottom of the vessel is usually filled with (untreated) wood chips, on which pieces of bark and other hiding places are distributed. Since the male animals use their horn-like outgrowths on the pronotum for ramming against competitors when they meet, care must be taken to provide a sufficiently large vessel with hiding places.
Phylogeny, taxonomy, systematics
The genus Gromphadorhina forms together with Elliptorhina , Princisia and a number of other (rarely found) genera a family of similar species, which is taxonomically taken as the tribe Gromphadorhini. Within the cockroach family Blaberidae, these belong to the African subfamily Oxyhaloinae. In a genetic investigation, the Oxyhaloinae and the Gromphadorhini, but not the genus Gromphadorhina, were found to be monophyletic units. The demarcation of the variable species, some of which are very similar today, is uncertain.
The species was first described as Hormetica portentosa in 1853 by the German entomologist Hermann Rudolf Schaum . It is a type species of the genus Gromphadorhina Brunner von Wattenwyl . According to today's view, this includes three other types.
gallery
Juvenile Madagascar hissing cockroach
Skinned Madagascar hissing cockroach (male)
Young cockroaches hatch
Young cockroaches hatch
Adult hissing cockroach (male)
Literature and Sources
- Christian Van Herrewege (1973): Contribution à l'étude des Blattaria de la Faune Malgache. II. Description de huit espèces nouvelles appartenant aux genres Gromphadorhina Brunner vW et Elliptorhina gen. Nov. Bulletin mensuel de la Société linnéenne de Lyon, 42ᵉ année, numéro hors-série décembre 1973. Journées entomologiques du 150e anniversaire de la Société linnéenne de Lyon: 75-103. doi: 10.3406 / linly.1973.10036
- Emmanuel Delfosse (2006): Sur la taxinomie, la répartition et la biologie des leaf souffleuses de Madagascar of the genre Elliptorhina van Herrewege, 1973; Gromphadorina Brunner, 1865 et Princisia van Herrewege, 1973 (Insecta: Blattodea: Blaberidae). Bulletin d'Arthropoda 30 (4): 3-32.
- Emmanuel Delfosse (2004): Les Blätteres souffleuses de Madagascar. Genres Elliptorhina Herrewege, 1973; Gromphadorhina Brunner, 1865 et Princisia Herrewege, 1973 (Insecta, Dictyopteroidea Blattodea, Blaberoidea, Blaberidae, Oxyhaloinae, Gromphadorhinini). Insectes 135 (4): 19-22.
- Frédéric Legendre, Philippe Grandcolas, France Thouzé (2017): Molecular phylogeny of Blaberidae (Dictyoptera, Blattodea) with implications for taxonomy and evolutionary studies. European Journal of Taxonomy 2017: 1–13. doi: 10.5852 / ejt.2017.291 .
- species Gromphadorhina portentosa (Schaum, 1853) . Cockroach Species File online (Version 5.0 / 5.0).
- Monique Meier, Daniel Horn (2017): Madagascar hissing cockroaches in class. Biologie in our time 47 (3): 194-197. doi: 10.1002 / biuz.201710623
- Margaret C. Nelson, Jean Fraser (1980): Sound production in the cockroach, Gromphadorhina portentosa: evidence for communication by hissing. Behavioral Ecology and Sociobiology 6 (4): 305-314. doi: 10.1007 / BF00292773
