Genus Extatosoma Gray, 1833

“Large; body broad and spinose in female, slenderer and less spinose in male. The male is winged, female with rudimentarywings. Head prognathous, dorsal apex conical and spinose. Three ocelli distinct in male, lacking in female. Antennae simple, of moderate length (much longer in male), pubescent. Mesonotum dilated in female, not twice length of pronotum. Forewings shortened. In male, oval, as long as metanotum; in female, broader, but little over half length of metathorax. Hindwings of male large, reaching to around apex of abdomen. In female shrivelled and rudimentary (shorter than forewings). Abdominal segments greatly expanded laterally, particularly 5th-7th segments. In female, paired median lamellae present on abdominal segments. Legs moderately long to short; femora and tibiae spinose, trigonate, broadly dilated, particularly in female. Mid and hind tibiae with apical hooked spine. Female with large boat-shaped operculum extending well beyond end of abdomen; valves long, filamentous, apically curved. Subgenital plate in male boat-shaped. End of abdomen a closed tube. The large eggs are very conspicuous. Capsule oval, with broad, slightly raised micropylar plate, extending full length of dorsal surface.” (Brock, 2002)

“Body large and spinose, the male winged, female brachypterous; certain middle segments of the abdomen of both sexes with lateral tergal lobes, these much more expanded in female than in male. Head prognathous, dorsal apex conical and spinose; ocelli distinct in male, lacking or evanescent in female; antennae simple moderately pubescent. Mesothorax dilated posteriorly, less than twice prothoracic length. Tegmina of both sexes abbreviate, those of female somewhat broader than those of male; wings of male extending about to or beyond apex of abdomen, of female abbreviate, sometimes shriveled and rudimentary. Legs moderately long to short; femora and tibiae spinose, trigonate, broadly dilated, more markedly so in female; ventral surface of middle and hind tibiae without apical triangular area, bearing apical hooked spine; basitarsus somewhat shorter than remaining tarsal segments. Ovipositor sheath of female boat-shaped and extending posteriorly beyond apex of abdomen; ovipositor valves long, filamentous, apically curved.” (Gurney, 1947)

Taxonomy

The genus consists of two species.

Extatosoma tiaratum
There is only one species on the Australian mainland, with two recognised subspecies.
Extatosoma popa
This species does does not occur in Australia.

Identification Key

Distribution

The distribution map is a hot-linked index. By clicking on a highlighted area of the map, you may obtain a species list for that area, within this genus.

Extralimital distribution: New Guinea, see Kirby, W.F. (1904). A Synonymic Catalogue of Orthoptera. Vol. 1. Orthoptera, Euplexoptera, Cursoria, et Gressoria (Forficulidae, Hemimeridae, Blattidae, Mantidae, Phasmidae). London: Longmans & Co. x 501 pp. [381].

Brock, P.D. (2002). Studies on the Australasian stick-insect genus Extatosoma Gray (Phasmida: Phasmatidae: Tropoderinae: Extatosomatini), Journal of Orthoptera Research, Dec. 2001, 10(2): 303-313

References:

Balderson, J., Rentz, D.C.F. and Roach, A.M.E. (1998). in Houston, W.K.K. & Wells, A. (1998) (eds) Zoological Catalogue of Australia. Vol. 23. Archaeognatha, Zygentoma, Blattodea, Isoptera, Mantodea, Dermaptera, Phasmatodea, Embioptera, Zoraptera. Melbourne: CSIRO Publishing, Australia (ISBN 0643 06035 9). pp. 347 - 376.
Brock, P.D. (2002). Studies on the Australasian stick-insect genus Extatosoma Gray (Phasmida: Phasmatidae: Tropoderinae: Extatosomatini), Journal of Orthoptera Research, Dec. 2001, 10(2): 303-313
Froggatt, W.W. (1922). Description of a new phasma belonging to the genus Extatosoma. Proc. Linn. Soc. NSW, 47: 344-345, pl. 38.
Gray, G.R. (1833). The Entomology of Australia in a Series of Monographs. Part 1. The monograph of the genus Phasma. London: Longman & Co. 28 pp. 8 pls
Gray, G.R. (1835). ‘Synopsis of the Species of Insects Belonging to the Family of Phasmidae.’ 48pp. (Longman, Rees, Orme, Brown, Green and Longman: London.)
Gurney, A.B. (1947). Notes on some remarkable Australasian walkingsticks, including a synopsis of the Genus Extatosoma (Orthoptera: Phasmatidae). Annals of the Entomological Society of America. 40(3): 373-396.
Rainbow, W.J. (1897). Catalogue of the described Phasmidae of Australia. Records of the Australian Museum, 3(2), 37-44. [Note that he made a mistake re Extatosoma popa and E. tiaratum according to Gurney, A.B. (1947). Notes on some remarkable Australasian walkingsticks, including a synopsis of the Genus Extatosoma (Orthoptera: Phasmatidae). Annals of the Entomological Society of America. 40(3): 373-396. .]
Tepper, J.G.O. (1902). List of the Described Genera and Species of the Australian and Polynesian Phasmidæ (Spectre-Insects). Transactions of the Royal Society of South Australia, 26: 278-287.
Tepper, J.G.O. (1903). Notes and remarks on the described genera and species of Australian and Polynesian Phasmidæ or ``spectre insects''. Victorian Naturalist, 19: 138-142.
Vickery, V.R. (1983). Catalogue of Australian stick insects (Phasmida, Phasmatodea, Phasmatoptera, or Cheleutoptera). CSIRO Australian Division of Entomology Technical Paper, No. 20, 15 pp.
Westwood, J.O. (1874). Thesaurus Entomologicus Oxoniensis: or illustrations of new, rare and interesting insects, for the most part coloured, in the collections presented to the University of Oxford by the Rev. F.W. Hope. London: McMillan & Co. i-xxiv, 205 pp., 40 pls

Synonyms:

Ectatosoma Gray, 1835