Phobaeticus foliatus (Bragg, 1995) 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 : 141-144

Phobaeticus foliatus (Bragg, 1995) comb. nov.

( Figs. 103–104, 229–231, 276, 312, 326–327, 380)

Nearchus foliatus Bragg, 1995b: 274 , figs. 1–5. HT, ♀: H.C. Siebers, Midden O-Borneo, 21. VIII. 1925 ( RMNH). Bragg, 2001: 389, fig. 146. [Description of ♂]

Otte & Brock, 2005: 209.

Further material [2 ♂♂, 1 ♀]:

BORNEO, KALIMANTAN:

1 ♂: H.C. Siebers, Midden O-Borneo, 12.X.1925, 160; Nearchus foliatus Bragg, 1995 , det. P.E. Bragg, II.1997 ( RMNH). N-BORNEO, SABAH [examined from photographs only] :

1 ♂: Borneo, Sabah, Mt. Kinabalu, Silau Silau Trail c. 5200’, 26 th September 1992; Coll. C.L. Chan & Poon (coll. CLC) ;

1 ♀: Silau-Silau Trail, 16.VIII.2006, Coll. MLT Bushell (coll. CLC).

Diagnosis: Related to Ph. redtenbacheri ( Dohrn, 1910) , but well characterized and easily distinguished from this and all other members of the genus by the spinose mesonotum, prominent leaf-like lobes of the legs and lateral lobes of abdominal tergites II–IX of both sexes.

Etymology: “ Foliatus ” (lat. = with leaf-like lobes) refers to the prominent leaf-like lobes of the legs of this spectacular species.

Description: Bragg (2001: 389) provided detailed descriptions of both sexes. The ♀ HT has suffered some damage: the right fore leg, parts of the left protarsus and most of the antennae are missing and the apex of the abdomen appears to have been laterally compressed during preservation. The description of the ♂ is based on the specimen in RMNH only.

♀♀ ( Fig. 103): Long (body length 192.0 mm; incl. subgenital plate 214.0 mm) and rather robust species (maximum body width 7.5 mm) with a long, lanceolate subgenital plate (41.0 mm), spinose mesonotum, laterally lobed abdominal tergites and striking leaf-like lobes on the legs. General colouration of body and legs almost uniformly mid-brown (HT) to greenish brown (♀ in coll. CLC). The latter specimen has the entire body set with irregular darker brown speckles, the bases of all femora pale brown and the legs prettily furnished with irregular pale transverse bands and pale brown mottling on the leaf-like appendages. Lateral appendages of abdominal tergites dark brown to black with conspicuous pale markings along the outer mar- gin. Eyes dark reddish brown.

Head: 1.4x longer than wide, globose, vertex convex and smooth. Eyes rather large, circular and projecting hemispherically; their length contained contained about 3x in that of cheek. Antennae rather long and reaching about half way along metanotum. Scapus dorsoventrally flattened, 3x longer than wide and narrowed towards the base. Pedicellus distinctly shorter than scapus, cylindrical. Following antennomeres very elongate and increasing in length.

Thorax: Pronotum slightly shorter and narrower than head, indistinctly longer than wide and slightly narrowed in anterior portion; lateral margins gently raised. Median transverse depression shallow, slightly curved and not reaching lateral margins of segment. Mesothorax very slightly widening towards the posterior and about 2.5x longer than head and pronotum combined. Mesonotum smooth dorsally, lateral margins each set with 2–5 distinct, more or less paired and 2–5 smaller irregularly positioned spines. Metanotum about 2.5x longer than wide, rectangular and lateral margins each set with three rather small spines. Meso- and metapleurae and sterna smooth.

Abdomen: Median segment ¾ the length of metanotum, parallel-sided, 2x longer than wide and with a small posteromedian tubercle. Segments II–VII increasing in length, II 2x and VII 3x longer than wide, all parallel-sided. Tergites II–IX with a small posteromedian tubercle and II–X each with an irregularly dentate, leaf-like lateral expansion in posterior half; this is large on II–VI, most prominent on VII (Fig. 276), small on VIII–IX and very indistinct on anal segment (X). Sternites II–VI smooth. Praeopercular organ formed by a pair of triangular lobes at posterior margin of sternum VII. Tergite IX slightly more than half the length of VIII. Anal segment with a broadly rounded posteromedian indention, the angles acute (Fig. 230). Supraanal plate small, triangular and keeled. Cerci reaching to apex of anal segment, slender and densely sethose. Subgenital plate strongly keeled, moderately lanceolate, tapered towards an acute apex and projecting by 22.0 mm (HT) over posterior margin of anal segment (Fig. 229); surface rugulose.

Legs: All long and slender, mid and hind legs densely armed with large teeth and furnished with large leaf-like lobes. Profemora a little longer than head, pro- and mesonotum combined, mesofemora almost as long as mesothorax, metafemora reaching to posterior margin of abdominal segment V and metatibiae roughly reaching apex of subgenital plate. Anterodorsal carina of profemora densely serrate, posterodorsal carina with a large foliaceous lobe 1/3 the way along femur and posteroventral carina with irregular triangular serrations of different sizes (Fig. 327). Posterodorsal carina of protibiae with three slightly enlarged triangular lobes in great distance and 3–4 lobes in apical portion. Posteroventral carina serrate and with a slightly enlarged triangular tooth about 1/3 the way along tibia. Meso- and metafemora with four large foliaceous lobes on posterodorsal carina, two outer ventral carinae sparsely dentate and with four paired, distinct triangular teeth in great distance to another (Fig. 326). Medioventral and anterodorsal carinae distinct but unarmed. Meso- and metatibiae with three large foliaceous lobes on posterodorsal carina and a small triangular tooth apically. Posteroventral carina dentate and with two prominent foliaceous lobes in basal portion, anteroventral carina serrate, medioventral and anterodorsal carinae unarmed. All basitarsi longer than following three segments combined, dorsal carina slightly raised and tri-dentate, ventral carinae minutely tri-dentate.

♂♂ ( Fig. 104): Medium sized (body length 124.0 mm) and moderately slender for the genus with long alae (49.0 mm), a spinose mesothorax, laterally lobed abdominal tergites and several acute triangular teeth and sometimes striking leaf-like lobes on the mid and hind legs. General colouration of body and legs greenish brown, mesonotum slightly darker and with a blackish longitudinal band along lateral margins. Tegmina and costal region of alae pale greyish or greenish brown and furnished with a few faint darker markings, veins sepia. Anterior margin of tegmina and basal portion of anterior margin of alae very pale green. Anal region of alae transparent grey with brown veins. Armature of legs mid brown, the leaf-like- lobes of the mid and hind legs to a variable degree mottled with pale cream. Bases of all femora straw to pale greenish brown. Eyes dull reddish brown with blackish mottling. Antennae mid brown and becoming paler towards the base.

Head (Fig. 312): Generally as in ♀♀ and slightly narrowed posteriorly. Eyes very prominent, almost spherical and projecting strongly from head capsule; length contained a little less than 3x in that of cheek. Antennae projecting over posterior margin of abdominal tergite II, otherwise as in ♀♀.

Thorax: Pronotum distinctly shorter and narrower than head, slightly longer than wide, posterior and anterior margin slightly raised. Transverse median depression shallow and almost straight, not reaching lateral margins of segment. Mesothorax slender and about 2.6x longer than head and pronotum combined. Mesonotum parallel-sided only very slightly widened at posterior margin and armed with 9–12 laterally directed small to medium spines (Fig. 312). Mesosternum with a faint longitudinal median carina. Metasternum and pleurae smooth. Tegmina just covering base of alae, elongate, oval and strongly constricted towards the base; central portion roundly convex. Alae reaching to middle of abdominal tergite V.

Abdomen: Median segment 2x longer than metanotum. Tergites II–VI ± 4.5 longer than wide, parallelsided and very slightly broadened at posterior margin. V and VI with a pair of small posteromedial tubercles. VII about 2/3 the length of VI, slightly widening towards posterior margin and 2.5x longer than wide. VIII 2/ 3 the length of previous, strongly convex, IX almost quadrate. Anal segment longer than VIII and IX combined, strongly tectiform and laterally compressed. Semi-tergites long, straight and slender with the apex rounded (Fig. 231). Interior surfaces with the outer margin raised and densely set with minute black teeth; a very few teeth in central portion. Cerci slender, round in cross-section and with the apex slightly in-curving and constricted. Poculum strongly convex, cup-like, almost reaching posterior margin of tergite IX and angular with a conical central hump.

Legs: All moderately long and slender, profemora longer than head, pro- and mesothorax combined, mesofemora as long as pro- and mesonotum combined, metafemora slightly projecting over abdominal segment VI and metatibiae slightly exceeding apex of abdomen. Anterodorsal carina of profemora with ± 20 irregular, acutely triangular serrations of variable sizes. Posterodorsal carina with a single tooth or prominent triangular lobe about ¼ off the base. Posteroventral carina serrate and with several enlarged triangular teeth in particular in the basal and apical portions. Posterodorsal carina of protibiae serrate and with 3–4 large teeth or tooth-like lobes, anterodorsal and posteroventral carinae minutely serrate. Mid and hind legs furnished with large leaf-like lobes similar to ♀♀ (coll. CLC), or the dorsal armature only represented by enlarged triangular teeth, all carinae acutely serrate. Medioventral carina of meso- and metafemora distinct but unarmed. All carinae of meso- and metatibiae minutely but acutely serrate, the posterodorsal carina with three triangular lobelike teeth or prominent lobes; generally as in ♀♀. Basitarsi longer than combined length of remaining segments, as in ♀♀.

Variation: Ph. foliatus shows considerable variability in particular concerning to the armature of the legs. The ♂ from Kalimantan in RMNH ( Fig. 104) and ♂ from Mount Kinabalu in coll. CLC appear to represent the opposite extremes of the variation range in this species, the armature being remarkably more strongly developed in the specimen from Mount Kinabalu. The posterodorsal carinae of the mid and hind legs of this specimen bear very prominent leaf-like lobes similar in shape and relative size to those seen in ♀♀, whereas these are only represented by enlarged, acutely triangular teeth on the hind legs of the ♂ from Kalimantan in RMNH (this specimen has the mid legs regenerated which probably accounts for the absence of foliaceous lobes, Fig. 104). The ♂ from Mount Kinabalu also has the lateral lobes of the abdominal tergites decidedly larger with the outer margin acutely dentate. These differences are also true but much less striking in the ♀ HT in RMNH ( Fig. 103) and ♀ in coll. CLC which are from the same two localities .

Comments: Bragg (1995b) described this remarkable species from a single ♀ in RMNH and originally included it in Nearchus Redtenbacher, 1908 which is a junior synonym of Phobaeticus Brunner v. Wattenwyl, 1907 (syn. nov.). This automatically transfers N. foliatus to Phobaeticus (comb. nov.). It is however remarkable for several characters which promptly distinguish it from all other members of the genus and entire tribe Pharnaciini , being the only representative with distinct spines on the mesonotum, large serrate lateral lobes on all abdominal tergites and numerous prominent, leaf-like appendages on the legs. Unfortunately the eggs are as yet unknown. Detailed comparison with other taxa of Phobaeticus have however, apart from the characters mentioned above, not revealed any features which would justify a separate generic placement of Ph. foliatus . The shape and structure of the head, antennae and genitalia are very typical for Phobaeticus and place it close to the sympatric Ph. redtenbacheri ( Dohrn, 1910) . The ♂ was subsequently described by Bragg (2001: 389) based on a specimen in RMNH from the same locality and source.

The appendages of the abdominal tergites and prominent leaf-like expansions of the legs show remarkable convergence to the Neotropical genus Trychopeplus Shelford, 1909 (Type species: Trychopeplus multilobatus Redtenbacher, 1908 ) a member of Diapheromeridae : Diapheromerinae : Diapheromerini .

Eggs unknown.

Distribution (Fig. 380): Central and NE-Borneo, endemic. Kalimantan (Middle East-Borneo) and Sabah (Mount Kinabalu National Park 1500 m).

Number of specimens examined: 4