Ctenomorpha gargantua, Hasenpusch, Jack & Brock, Paul D., 2006

Hasenpusch, Jack & Brock, Paul D., 2006, Studies on the Australian stick insect genus Ctenomorpha Gray (Phasmida: Phasmatidae: Phasmatinae), with the description of a new large species, Zootaxa 1282, pp. 1-15 : 9-13

Ctenomorpha gargantua spec. nov. [Gargantuan Stick­insect]

( Figs. 7–10 )

Ctenomorpha sp. Brock 1999: 122, pl. 8.

Description

Male (holotype) ( Figs. 7­8 ): Elongate, dark brown insect with light blotches. Body length 189 mm.

Head: Longer than broad, eyes large; three conspicuous ocelli present between eyes. Antennae with 26 segments; reaching half length of fore tibiae.

Thorax: Elongate, with few sparse granulations and tubercles dorsally and laterally.

Pronotum shorter than head, with bold central indentation and lines beneath. Mesonotum less than seven times length of pronotum, ventrally pale yellowish brown, with a glossy, central, oval black area, grey in the centre, with two black dashes within; this peculiar feature has not been seen in other phasmids (possibly useful in defence i.e. could be mistaken for a large eye, conspicuous ventrally or laterally). Metanotum short.

Abdomen: Remarkably elongate, sparsely granulated. Abdominal segments 8 to 10 only marginally longer than segment 7. Segments 7­10 slightly hairy. Cerci broad, leaflike, almost three times longer than 10th (anal) segment. Subgenital plate subtruncate at tip, not quite reaching end of 9th abdominal segment. 9th segment rather narrowed, but broadened at tip; anal segment shorter, boldly triangular incised in centre; claspers beneath with four short black teeth.

Wings: Forewings long, leaf­like, with whitish margin. Pre­anal part of hindwings with continuing whitish margin, sometimes same as body colour, as are forewings. Hindwings brown, long, but only reaching end of 5th abdominal segment (hence relatively short in male phasmids, but only due to the extremely elongated abdomen).

Legs: Very slender and elongate, with series of small dentations, except fore tibiae. All femora with pair of bold apical spines. Central carina of fore femur with nine large dentations (left fore leg broken off and missing). Mid and hind femora with two bold central dentations on central and outer carina (except regenerated right mid leg). Two additional dentations on right femur. Tarsi long.

Paratype males (8 specimens, fig. 9).

Same as holotype except for minor size differences (body length 170­198 mm) and minor variation in number and size of dentations on legs (in some specimens there are up to two large dentations on mid and hind tibiae), and extent of granulations / tubercles.

Notes on the female: (fig. 10)

Unfortunately not available for description, the only definite female of this species is from photographs of a 300 mm specimen found in the Evelyn Tablelands, north Queensland, 3,000 ft., by Mr T. Fayne­Scott, on 28 March, 1996. The previous record for the longest Australian phasmid was Acrophylla titan Macleay, 1826 (up to 270 mm). The overall length of A. titan at c. 390 mm is dwarfed by C. gargantua at c. 525 mm, based on a tape measure used on one photograph. In fact, gargantua is only exceeded in body length by a new Phobaeticus species (357 mm) and Phobaeticus kirbyi (328 mm), both from Sabah. However, Asian species from the closely­related genera Nearchus Redtenbacher, 1908 and Phobaeticus Brunner, 1907 , compete with C. gargantua for the rank of thirdlongest insect in the world.

From the photograph, it is apparent that the specimen of gargantua has a protuberance mid­abdomen. This is a variable feature in C. marginipennis , but often absent.

Holotype ♂, Australia: Mourilyan Harbour , n[orth] Q[ueensland], 1.xi.1996, J. & P. Hasenpusch ( QMBA). Paratypes: All Australia: ♂, Garradunga , n[orth] Q[ueensland], 28.xii.1996, P. Hasenpusch ( QMBA), 3♂, 16º48’S, 145º38’E (GPS), Qld, Kuranda (335m elev.), ( Top of the Range ), 19 Butler Dr, 25­30.xi.2004 (also 1­15.xii.2005 & 1­ 15.ii.2006), D. C. F. Rentz ( ANIC), ♂, 16º48’S, 145º38’E (GPS), Qld, Kuranda (335m elev.), ( Top of the Range), 19 Butler Dr , 1­15.xi.2005, D. C. F. Rentz ( BMNH), ♂, Polly Creek, Garradunga , north Queensland, 16.i.2005, J. Hasenpusch ( P. Brock coll.), 2♂, Polly Creek, Garradunga , north Queensland, 18.xii.2001 & 15.iii.2000, J. Hasenpusch ( J. Hasenpusch coll.) .

Distribution

So far found in rainforest in a small part of northeast Queensland, where males are attracted to light. Likely to be much more widespread.

Figures

FIGURE 7. Ctenomorpha gargantua holotype male, showing a) fore leg serration, b) ventral surface of mesonotum, showing glossy black area in centre (QMBA).

FIGURE 8. Ctenomorpha gargantua end of abdomen, in holotype male (QMBA), lateral view.