Adult skull cockroach ( Blaberus craniifer ) with larvae
|Burmeister , 1838|
The skull cockroach or, more rarely, the giant forest cockroach ( Blaberus craniifer ) is a species of cockroach (Blattodea) that is relatively well-known due to its presence in pet shops . There it is usually offered as food for terrarium animals that need large live food. Distinctive feature is often described as a skull similar to drawing on the neck plate .
With a body length of usually 50 to 53 millimeters and a total length of 60 to 65 millimeters due to the wings protruding above the abdomen , the species is one of the larger cockroaches. In exceptional cases, females can also reach a body length of 62 millimeters. At around 18 millimeters wide, the body of the males is somewhat narrower than the average 21 millimeter wide body of the females. Both sexes have antennae about 30 millimeters long , are about 10 millimeters high, and are fully winged. The cover wings are designed as tegmina and protrude beyond the body not only at the rear, but also at the sides. This gives them a total width of 27 to 30 millimeters. While the legs are dark brown and the body is patterned light and dark brown, the wings are dominated by a light brown basic color. On the forewings, this becomes darker towards the rear. At the same time there is a medium brown line beginning at the base of the wing between the subcostal and anal field (see also venation and cells of the insect wing). On the right wing this ends, widened somewhat towards the rear, after about a third to almost half of the wing length. On the left wing it extends broadly to the medial margin. When the wings are closed, the impression of a very light spot surrounded by brown areas behind the pronotum is often created. The width and shape of this wing mark are age-dependent and vary greatly. Older animals in particular often appear darker and do not show the high-contrast drawing that is particularly typical for freshly adult animals. The pronotum shows a dark spot on a light brown background that extends to the rear edge. In turn, it can have small, bright spots. The resulting image is often perceived as being similar to a skull, which has given the species its common name . Females have a larger pronotum. In addition, the last two abdominal sternites have grown together. These form a plate that is clearly triangular in outline.
Occurrence and behavior
The distribution area extends over Mexico , Belize , Cuba , the Dominican Republic and Florida . A further spread by humans cannot be ruled out. In some places the entire tropical Central and South America is named as the distribution area .
While the young are more active at night and hide during the day, the adults can also be found in shady areas during the day when the humidity is higher. Just like sexually mature animals, the young are able to excrete a strongly smelling secretion to ward off enemies.
The skull cockroach is ovoviviparous . The dark brown ootheca contains an average of 34 eggs. It is carried by the female in a specially designed genital pouch for three to four weeks until hatching . A female with a fully developed ooth can weigh up to five grams. The six to seven millimeters long, isle-shaped larvae hatch immediately after the egg package has been set down. They have a vivid pattern of light and dark brown and take around four to five months to reach adulthood . Life expectancy is then around one year.
Hermann Burmeister described the skull cockroach in 1838 as Blabera craniifer . The generic name he used is based on a term used at times, but later recognized as incorrect, of the genus Blaberus, which was correctly established by Jean-Guillaume Audinet-Serville in 1831 . Burmeister described the species in the same publication that also contained the first description, wrongly under two other names, which gave rise to the first synonyms . Due to the large distribution area and the variety of the species, further descriptions followed by other authors. The following names are now considered synonymous with Blaberus craniifer :
- Blabera limbata Burmeister , 1838
- Blabera trapezoideus Burmeister , 1838
- Blabera varians Serville , 1839
- Blabera luctuosa Stål , 1855
- Blatta atropos Guérin-Méneville , 1857
- Blabera ferruginea Saussure , 1864
- Libisoca aequalis Walker , 1868
- Blabera quadrifera Walker , 1868
- Blaberus craniipes
Man and cockroach
The skull cockroach found its way into lovers' terrariums early on . At first, the species was used as a foster animal due to its size and sometimes also as an experimental animal in studies and teaching. In the meantime it is primarily kept and bred as a food animal for insect eaters, mostly larger lizards. It should be noted that because of the strong-smelling defense secretion, not all insectivores eat this cockroach species. Occasionally the species appears as a pest in human dwellings.
- Erich Kleinsteuber: Small animals in the terrarium , Urania-Verlag Leipzig Jena Berlin 1998, p. 110, ISBN 3-332-00273-2
- Siegfried Löser: Exotic insects, millipedes and arachnids - instructions for keeping and breeding . Ulmer, Stuttgart 1991, pp. 25-26, ISBN 3-8001-7239-9
- Ursula Friederich & Werner Volland: Futtertierzucht , 2nd edition. Eugen Ulmer, Stuttgart-Hohenheim 1992, pp. 27-74. ISBN 3-8001-7230-5
- Ingo Fritzsche : Riesen unter den Schaben , Arthropoda 16 (4) December 2008, p. 14, Sungaya-Verlag Kiel.
- GW Beccaloni: Blattodea Species File Online . 2007. Version 1.2 / 4.0. World Wide Web electronic publication. (accessed on January 29, 2011)