Phobaeticus rex ( Günther, 1928 ) Hennemann & Conle, 2008

Hennemann, Frank H. & Conle, Oskar V., 2008, 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, pp. 1-316 : 180-182

Phobaeticus rex ( Günther, 1928) comb. nov.

( Figs. 118, 265, 270, 331, 391)

Eucarcharus rex Günther, 1928: 218 . HT, ♀: Sumatra, Redjang-Lebong, leg. H. Kubale S.; Eucarcharus rex Günther, 1928 (MNHU).

Lobophasma rex, Günther, 1935b: 138 . Günther, 1953: 555. Zompro, 2005b: 279. Otte & Brock, 2005: 178.

Phobaeticus lambirica Seow-Choen, 1998a: 40 , fig. 1 (♀ and egg). HT, ♀: Malaysia, Sarawak, Lambir National Park, Dec. 1996, I. Abercrombie (SFDK) syn. nov. Otte & Brock, 2005: 269.

Baculolonga lambirica, Bragg, 2001: 384 .

Diagnosis: Easily distinguished from all other members of the genus by the remarkable long and leaf-like, posteriorly dentate lateral lobes of abdominal tergite VII, which project by distinctly more than the body width and long supraanal plate.

Etymology: “ Rex ” (lat. = king) refers to the great size of this striking species.

Description: ♀♀ ( Fig. 118): Very long (body length 247.0–260.0 mm) and moderately slender species for the genus (7.0–8.0 mm). General colouration of body light to mid brown with large areas of white on head, thorax, abdominal tergites and all legs, occasionally greenish areas near anterior and posterior margin of the mesonotum and lateral regions of the metanotum. Head generally whitish with a bold transverse dark brown band along posterior margin and a pair of black, roughly C-shaped spots between the eyes. Most parts of meso-, metanotum, median segment, tergites III and V–X whitish. Tergite II with two bold black converging stripes and a large, white and wedge-shaped marking at the posterior. Tergite IV with a pair of similar but smaller black markings. Ventral surface of body generally orange brown with irregular greenish and whitish speckles. Meso- and metasternum with a green longitudinal median line, the latter with two elongate greenish white markings. Abdominal sternites more or less distinctly mottled with white. Legs white and distinctly marbled with grey or brown. Tarsi yellowish brown with darker mottling. Eyes sepia with darker brown speckles. Antennae reddish brown, except for two basal segments.

Head: Elongate, oval, almost 2x longer than wide, cheeks almost parallel-sided, vertex gently convex in posterior portion. A distinct transverse depression between the bases of the antennae. Eyes small, circular and moderately convex; their length contained about 3.5x in that of cheeks. Antennae at least with 29 joints and reaching 1/3 the way along mesonotum. Scapus dorsoventrally flattened, parallel-sided, 3x longer than wide and almost 3x longer than pedicellus; the latter round in cross-section.

Thorax: Pronotum shorter and narrower than head, almost rectangular and parallel-sided, the anterior portion very indistinctly constricted; about 1.5x longer than wide. Median transverse depression indistinct, straight and not reaching lateral margins of segment. Mesothorax about 2.8x longer than head and pronotum combined, mesonotum parallel-sided except for being very gently widened at posterior margin. Metanotum about 2/5 the length of mesonotum, 3x longer than wide. Meso- and metapleurae with a very fine longitudinal median carina. Meso- and metasternum simple.

Abdomen: Median segment ¾ the length of metanotum, parallel-sided, about2.4x longer than wide. Abdominal segments II–VI increasing in length, II about equal in length to median segment and 2x longer than wide, IV 3.5x longer than wide. V as long as IV, VI as long as III. Tergites II–VII with posterior margin roundly arcuate and forming a blunt posteromedian tubercle. VI and VII with an indistinct longitudinal median carina. Lateral margins of VII posteriorly protruded into a very long, leaf-like lobe which projects by considerably more than the body width and reaches as far back as to the middle of VIII (Fig. 270); posterior margin roughly dentate. Sternites II–VI with an indistinct blunt median carina. Praeopercular organ formed by two small spiniform tubercles at posterior margin of sternum VII. Tergite VIII distinctly narrower than previ- ous, about ¾ the length of VII, strongly convex, constricted medially and about 3.5x longer than wide. IX indistinctly longer than wide, half the length of VIII, rectangular. Anal segment slightly longer than IX and with a fine median carina, posterior margin with a broad, trapezoidal excavation. Supraanal plate elongate, keeled and projecting distinctly over apex of anal segment. Subgenital plate strongly convex, boat-like, longitudinally keeled and not reaching to apex of supraanal plate (Fig. 265).

Legs: All long and moderately robust, meso- and metatibiae gently down-curving. Profemora about as long as mesothorax, mesofemora distinctly shorter than mesothorax, metafemora slightly projecting over posterior margin of abdominal segment IV and metatarsi slightly projecting over apex of abdomen. Anterodorsal carina of profemora with 10–12 very prominent, lamellate serrations of variable size, some of which may be distinctly enlarged and foliaceous posteroventral carina armed with ± 15 moderately distinct, acute teeth and elevated into a dentate lobe apically. Protibiae with anterodorsal carina distinctly but irregularly elevated and broadly, acutely wave-like. Posteroventral carina densely but rather minutely serrate. All carinae of mid and hind legs rather regularly dentate, less distinctly on dorsal carinae. Meso- and metafemora with a few minute spines on medioventral carina. Mesofemora with one or two prominent, long sub-basal spines on posteroventral carina and a broadened triangular tooth at same height on posterodorsal carina (Fig. 331). Metafemora without any larger spines or teeth. Posterodorsal carina of meso- and metatibiae with a prominent, broad triangular lobe medially and a deeply dentate lobe apically. Probasitarsus as long as remaining tarsomeres combined except claw, dorsal carina distinctly raised but unarmed, ventral carinae dentate. Meso- and metabasitarsi as long as following three tarsomeres combined, dorsal carina forming a considerably raised and rounded lobe; all carinae dentate.

* according to Seow-Choen (1998a: 41)

Eggs: Seow-Choen (1998a: 41) briefly mentioned and illustrated the eggs in lateral view and provided the following brief characterization: “The eggs of the new species is in the mould of a typical egg of other Phobaeticus species. The egg itself is very dark grey almost black and measures 6 mm by 3.8 mm. It is rather more globular than the egg of P. serratipes (Gray) and P. kirbyi Brunner and is 3.8 mm thick.” The author mentioned the egg to be typical for the genus and although only illustrated in lateral view the capsule is seen to be surrounded by a distinct dorso-ventral keel and notched near the polar-area. The capitulum is small and knoblike, the operculum oval. Unfortunately Seow-Choen did not probvide a description of the micropylar plate.

Measurements according to Seow-Choen (1998a: 41) [mm]: length 6.0, width 3.8, height 3.8.

Comments: Günther (1928: 218) presented a very detailed description and illustration of the HT of his Eucarcharus rex from SE-Sumatra in MNHU. Subsequently, Günther (1935b: 139) designated E. rex as the type species of his new genus Lobophasma , which is a junior synonym of Phobaeticus Brunner v. Wattenwyl, 1907 (syn. nov.). The HT of the Bornean Phobaeticus lambirica Seow-Choen, 1998a was only examined from colour photographs of the live insect. Comparison with the HT of Eucarcharus rex in MNHU however has clearly shown these two taxa to represent the same striking and characteristic species (syn. nov.). The disjunct distribution in SE-Sumatra and W-Borneo is remarkable.

♂ unknown.

Distribution (Fig. 391): SE-Sumatra (Redjang-Lebong) and W-Borneo ( Sarawak: Lambir National Park).

Number of specimens examined: 1