Extatosoma

Extatosoma
	Australian rock insect ( Extatosoma tiaratum ), female
Systematics
Class :	Insects (Insecta)
Order :	Ghost horror (Phasmatodea)
Family :	Phasmatidae
Subfamily :	Extatosomatinae
Tribe :	Extatosomatini
Genre :	Extatosoma
Scientific name of the subfamily
	Extatosomatinae
	Sellick, 1997
Scientific name of the tribe
	Extatosomatini
	Sellick, 1997
Scientific name of the genus
	Extatosoma
	GR Gray , 1833

left the lichen form of Extatosoma popa (formerly Extatosoma popa carlbergi ), next to it Extatosoma tiaratum

Lichen form of Extatosoma tiaratum

Extatosoma is a genus of the order of Gespenstschrecken (phasmatodea). It is the only genus of the subfamily Extatosomatinae and its tribe Extatosomatini .

Systematics

Due to the revision of the oriental Phasmatodea carried out by Frank H. Hennemann and Oskar V. Conle in 2008 , the genus Extatosoma within the family Phasmatidae has its own subfamily (Extatosomatinae) with a tribe (Extatosomatini). After up to six different species had been assumed for a very long time, a distinction was later only made between two species, each with two subspecies . Since 2010 only the two subspecies considered as nominate forms have been valid. All other names are synonymous and only describe local variants or environmental morphs .

Extatosoma tiaratum ( MacLeay , 1827)
( Syn. = Extatosoma hopii Gray, GR , 1833)
(Syn. = Extatosoma bufonium Westwood , 1874)
(Syn. = Extatosoma elongatum Froggatt , 1922)
Extatosoma popa Stål , 1875
(Syn. = Extatosoma carlbergi Beccaloni , 1993)

features

Both representatives of the genus look very similar and are 100 to 160 mm long in the female sex, 75 to 115 mm in the male, whereby the Australian ghost insect ( Extatosoma tiaratum ) remains somewhat smaller on average. The plump females have a mesothorax that widens conically towards the rear . The metathorax and the abdomen , which is greatly thickened in egg-laying animals, are cylindrical in cross-section. The abdominal segments five to seven are laterally enlarged by leaf-like lobes (lobes), which are larger in females than in males. In the females there are thin spines on the upper side of the abdomen, which in the growing female nymphs can be recognized after the second moult and thus enable a differentiation of the sexes. In both sexes, the forewings are only about 1.5 cm long tegmina . In the females the hind wings (alae) are almost completely reduced. In contrast, these are fully developed in the males and almost completely cover the abdomen. Your front area, the heavily sclerotized costal field , is placed over the rear area, the anal field , to protect it . The anal area is brown to black-brown. The limbs of both sexes are leaf-like widened and thorn on the edge. The head tapers conically to the forehead and has a species-specific crown of thorns. Males have three single eyes ( ocelles ) on their foreheads .

The variants of both species, which were regarded as nominate form in the past, are mostly almost monochrome. The color spectrum ranges from beige to green-yellow, yellow-brown and red-brown to almost dark brown. The females are usually a little lighter than the males. The colors get a little darker with age. With this coloring and a corresponding posture, they imitate wilted leaves almost perfectly ( phytomimesis ). The females of the other variants are marked much more vividly in both species and are characterized by a pattern of green, black and white spots, which make them resemble lichens or mosses . According to the type of phytomimetry, the monochrome variants are also called leaf imitators or leaf shape, while the more vividly drawn variants are called lichen shapes.

Occurrence and way of life

Extatosoma tiaratum is now only found in the tropics and subtropics of Australia . A population documented for the lichen form of Extatosoma tiaratum (formerly Extatosoma tiaratum bufonium or Extatosoma bufonium ) from Lord Howe Island has become extinct. Extatosoma popa is native to New Guinea . Lichen forms are mostly found in higher, because more humid, areas.

Both species are polyphagous herbivores . To eat, the animals move slowly over the food plants, preferably at night, in a rocking step that mimics the wind. Only the flying males actively search, e.g. Sometimes flying after sexually mature females, orienting themselves on their pheromones . Nymphs and females usually have their abdomen bent over their heads like a scorpion, which primarily improves camouflage, but also serves as defense, especially if it is accompanied by clicking noises. In addition, like most ghosts, they have the ability to throw off extremities at predetermined breaking points between the thigh ( femur ) and thigh ring (trochanter) ( autotomy ) and to partially replace them again during the next larval moult ( regeneration ). Various other defense mechanisms are also used. For example, the animals rock when there is wind or when something is moving in the area to imitate withered leaves in the wind. Furthermore, a musty to toffee-smelling secretion is sprayed from the defensive glands of the prothorax . Imagines and older nymphs also hit attackers with their upward stretched hind legs in order to pinch them between the thighs and the splint ( tibia ) and to injure or frighten and chase them away by means of the thorns on the edges of the legs .

newly hatched nymph of the Australian bug insect ( Extatosoma tiaratum )

In addition to sexual reproduction, the Extatosoma species are also capable of parthenogenesis . The shiny eggs, between 3.8 and 5.2 mm long and 2.8 to 4.8 mm wide, have a yellowish base color and marbled black-brown. While the micropylar plate of Extatosoma tiaratum is only widened at the level of the micropyle , here in Extatosoma popa there are two lateral branches, so that the micropylar plate forms a cross. The 400 to 1000 eggs are thrown away by the females with a quick movement of the abdomen. The capitula on the lids of the eggs have the same function as the elaiosomes of the seeds of myrmekochorer plants. However, they vary greatly between populations, just like the eggs themselves. The fire ants of the genus Leptomyrmex collect the eggs attracted by the capitula and bring them into the storage chambers of the ant nest. It is very likely that the capitulum of the eggs is consumed here. Due to the climate in the buildings, the nymphs can develop very well and above all protected and hatch there. In the first two to three days they are very similar to the fire ants in terms of behavior, body shape and color, so that they can leave the ant den unharmed. The development time of the embryos in the eggs is about five to nine months, in exceptional cases up to 19 months. Hatching Extatosoma tiaratum have a dark brown, almost black body, a white collar and a bright orange-red head. A local form is known from the south of Queensland , which differs from them both by the eggs and the hatchlings. These are very bright, have a red head and an orange chest ( thorax ). Thus they resemble the hatchlings of the animals originally known as Extatosoma bufonium . These also have a lighter, more red chest ( thorax ). Hatching Extatosoma popa are completely black. It takes about four to six months for the male nymphs to develop into adults after five and the female after six moults . Adult males reach an age of three to five months. Females usually live more than six months, but rarely up to a year.

Terrarium keeping

The Australian ghost insect ( Extatosoma tiaratum ) is one of the longest breeding and still best known ghost insects. It is considered to be easy to breed and can a. with blackberry , raspberry , currant , rose , oak , beech , Rotdorn- , or hawthorn leaves to feed. The Phasmid Study Group has them under PSG number 9. Extatosoma popa is much less common or not at all in breeding. It is listed under PSG number 21.

swell

^ Frank H. Hennemann & Oskar V. Conle : Revision of Oriental Phasmatodea: The tribe Pharnaciini Günther, 1953, including the description of the world's longest insect, and a survey of the family Phasmatidae Gray, 1835 with keys to the subfamilies and tribes ( Phasmatodea: "Anareolatae": Phasmatidae) (Zootaxa 1906), Magnolia Press, Auckland, New Zealand, 316 pp .; 30 cm. 15 Oct. 2008, ISBN 978-1-86977-271-0 (paperback), ISBN 978-1-86977-272-7 (online edition) (pdf of the abstract at www.mapress.com ; PDF; 48 kB)
^ ^A ^b Roy Bäthe, Anke Bäthe & Mario Fuß: Phasmiden , Schüling Verlag, Münster 2009, pp. 131-133, ISBN 978-3-86523-073-7
↑ ^a ^b ^c ^d ^e ^f Paul D. Brock & Jack W. Hasenpusch : The complete fell guide to stick and leaf insects of Australia , Csiro Publishing, Collingwood, Australia, 2009, pp. 126–128, ISBN 978-0-643 -09418-5
^ ^A ^b Paul D. Brock: Phasmida Species File Online . Version 5.0 / 5.0 (accessed November 18, 2018)
↑ ^a ^b ^c Christoph Seiler, Sven Bradler & Rainer Koch: Phasmids - care and breeding of ghosts, stick insects and walking leaves in the terrarium - bede, Ruhmannsfelden 2000, pp. 72–73, ISBN 3-933646-89-8
^ Eugène Bruins: Illustrated Terrariums Encyclopedia - Dörfler Verlag, Eggolsheim 2006, pp. 74-75, ISBN 978-3-89555-423-0
↑ Siegfried Löser: Exotic insects, millipedes and arachnids - instructions for keeping and breeding . Ulmer, Stuttgart 1991, pp. 43-44, ISBN 3-8001-7239-9
↑ Stephan Schorn: The Australian giant ghost insect Extatosom tiaratum , Natur und Tier Verlag, Münster 2009, ISBN 978-3-86659-123-3
↑ Phasmid Study Group Culture List (English)