Phobaeticus trui, Bresseel & Constant, 2014

Bresseel, Joachim & Constant, Jérôme, 2014, Giant Sticks from Vietnam and China, with three new taxa including the second longest insect known to date (Phasmatodea, Phasmatidae, Clitumninae, Pharnaciini), European Journal of Taxonomy 104, pp. 1-38 : 27-34

Phobaeticus trui sp. nov.

urn:lsid:zoobank.org:act:170DDF9E-44F6-452E-B6CC-740267ABF905

Figs 9A–N , 11C–D

Diagnosis

Females can be distinguished from all other members of the genus by the shape of the praeopercular organ ( Fig. 9C ) Males can be distinguished by the length of the alae and the shape of the semitergites. ( Fig. 9G–L ).

Etymology

The species is dedicated to our Vietnamese colleague Vu Tru Hoang (IEBR), better known as “Mr Tru”.

Type material

Holotype

VIETNAM: ♂, Bach Ma N.P., 16°12’ N, 107°52’ E, 12–17 Jul. 2011, leg J. Constant & J. Bresseel, I.G. 31.933 ( RBINS).

Paratypes (3 ♂♂, 2 ♀♀, 3 ♀♀ nymphs in penultimate stadium)

VIETNAM: 2 ♂♂, 2 ♀♀, 3 ♀♀ nymphs: same data as HT ( RBINS; 1 ♂, 1 ♀: VNMN); 1 ♂, Da Krong Nat. R., Quang Tri Prov., 16°37’ N, 106°47’ E, 5–10 Jul. 2011, leg. J. Constant & J. Bresseel, I.G. 31.933 ( RBINS).

Differentiation

Similar to Phobaeticus ingens ( Redtenbacher, 1908) from Myanmar and India, P. rex (Günther, 1928) from Peninsular Malaysia and Sumatra, and also P. hypharpax (Westwood, 1859) and P. lobulatus ( Carl, 1913) , both from Sri Lanka.

Males can be easily distinguished from P. ingens and P. hypharpax by their considerably shorter alae, which only reach the posterior margin of abdominal segment II, while these project beyond the posterior margin of abdominal segment IV in P. ingens and P. hypharpax . Males of P. rex and P. lobulatus are unknown.

Females can be distinguished from all closely related species by the strongly developed bilobed praeopercular organ. Furthermore it can be differentiated from P. rex , P. hypharpax and P. lobulatus

by the small lateral lobes of abdominal tergum VII. From P. ingens they can be differentiated by the relatively longer median segment, which is more than 2/3 the length of metanotum.

Description

The colouration is described from photographs of live specimens. Measurements, see Table 4 .

Male ( Fig. 9G–L )

BODY. Large (body length 172.4–190.4 mm) with short alae (23.4–25.8 mm).

COLOURATION. Head, pronotum, margins of mesonotum and metanotum pale brown, mesonotum except margins greenish blue. Abdominal segments II–VII pale brown, with black transverse band posteriorly. Segment VIII pale brown and segments IX–X pale brown with some whitish markings. Tegmina and costal region of alae pale brown with central portion darker brown and with anterior margin white. Anal region transparent grey with brown veins. Profemora with carinae black and paler markings in between. Meso- and metafemora with carinae greenish blue and black saw-like teeth, other areas of meso- and metafemora brownish pink. Tibiae and tarsomeres dark brown with several distinct pale transverse bands.

HEAD. Elongate, oval, about one third longer than wide, slightly narrowing basally and with faint impressed median line and two faint impressed lines on each side of head. Posterior portion with two longitudinal lateral impressions at each side of coronal-line. Slightly raised, smooth, C-shaped area between eyes. Eyes very prominent, strongly convex and projecting hemispherically. Antennae almost reaching median segment. Scapus dorsoventrally flattened with longitudinal impression ventrally. Pedicellus short, cylindrical. Length of antennomeres increasing towards apex of antennae.

THORAX. Pronotum distinctly shorter and narrower than head, 1.3x longer than wide, posterior margin broader than anterior one. Anterior margin raised, followed by transverse depression and short longitudinal indentation turning into a longitudinal median line. Median transverse depression distinct, not reaching lateral margins of segment. Mesothorax smooth and elongated, 3x to almost 3.5x longer than head and pronotum combined. Tegmina projecting over anterior margin of metanotum, elongated, narrowed basally. Alae reaching about halfway along abdominal tergum II.

ABDOMEN. Segments II–V slightly increasing in length and roughly of equal width, all slightly constricted medially. Tergum V with distinct hump posteromedially; VI and VII slightly shorter than previous; VI slightly broadened posteriorly; VIII 2/3 as long as VII and strongly broadened posteriorly; IX slightly longer than VIII, but distinctly narrower, broadened anteriorly and constricted medially. Anal segment longer than IX, laterally compressed and tectiform. Semi-tergites elongated, tapered but not pointy and gently down-curving. Interior surface densely covered with minute black teeth (thorn-pads). Cerci elongated, cylindrical in cross section, in-curving and tapered apically. Poculum reaching about halfway along tergum IX, strongly convex and cup-like.

LEGS. All very elongated, profemora longer and mesofemora almost as long as head, pro- and mesothorax combined, metafemora reaching about halfway along abdominal segment VI and metatibiae surpassing apex of abdomen. Anterodorsal carina of profemora with 7–15 prominent saw-like teeth. Posterodorsal carina sometimes with 1–2 small, triangular teeth. Posterodorsal carina smooth. Posteroventral carina with 5–12 small, pointed teeth. Anterodorsal carina of protibiae sometimes with small triangular lobe, otherwise unarmed. All carinae of meso- and metafemora prominent, armed with several black small, saw-like teeth. Ventral carinae of meso- and metatibiae with minute serrations all long. Anterodorsal carina serrated and with larger, triangular pre-medial teeth. Posterodorsal carina also with small serrations. Basitarsi with uniformly raised dorsal carina, longer than remaining segments combined. Dorsal carina of all tarsi resulting in a posteromedian lobe, projecting over following tarsus. Claws prominent.

Female ( Fig. 9A–F )

BODY. Very long (body length 243–266 mm), broad and sturdy species.

COLOURATION. General colour of body and legs mid to dark brown, with numerous irregular paler and darker markings and spots. Forelegs and meso- and metatibiae with more or less distinct dark transverse bands. Armature of legs reddish brown to black. Eyes pale brown. Antennae dark greyish brown.

HEAD. Elongate, oval, 1.6x longer than wide, slightly narrowing basally; vertex smooth and gently convex. Two transverse median impressions, one between antennae and one between eyes. Eyes large, strongly convex and projecting laterally. Antennae filiform, rather short, not reaching apex of profemora. Scapus dorsoventrally flattened. Pedicellus cylindrical, shorter than first antennomere.

THORAX. Pronotum shorter and narrower than head, about 1.3x longer than wide, posterior margin broader than anterior margin, slightly constricted centrally. Anterior margin with three small, holelike impressions, one central and two antero-lateral. Antero-median impression followed by median longitudinal line. Median transverse depression distinct, not reaching lateral margins. Mesothorax parallel-sided except for gradually widening posterior part, about 3.5x longer than head. Mesonotum with very faint longitudinal median line. Metanotum slightly more than 1/3 as long as mesonotum. Small, yet distinct posteromedian granule. Vestigial wings visible as small scales.

ABDOMEN. Median segment slightly shorter than metanotum. Segment II about as long as median segment. Terga III–V slightly increasing in length; V and VI of same length, with indistinct posteromedian hump; VII about as long as IV. Praeopercular organ distinct, represented by a pair of large lobes at posterior margin of sternum VII. Ventral view of praeopercular organ inverted heart-shaped about 1/3 the length of sternum VII. Tergum VIII distinctly shorter than previous and strongly convex; IX about half as long as VIII and strongly convex. Anal segment 1.5x length of IX, with fine median carina and widely triangular indentation at posterior margin, outer angles triangular. Supra-anal plate small, strongly keeled and rounded, not projecting beyond outer angles of anal segment. Cerci small, slightly flattened dorso-ventrally, oval in cross-section, finely setose and slightly exceeding anal segment. Gonapophyses filiform, up-curving but not reaching apex of anal segment. Subgenital plate longitudinally keeled, boatshaped and reaching posterior margin of anal segment.

LEGS. All long and broad, profemora slightly longer than combined length of pro- and mesonotum; mesofemora about as long as mesothorax; metafemora reaching over halfway the abdominal segment V and metatarsi nearly reaching apex of abdomen. Anterodorsal carina of profemora with 9–13 prominent, broad and undulate serrations. Posterodorsal carina sometimes with 4–8 small, triangular teeth. Posteroventral carina with 10–16 broad and undulate serrations. Anteroventral carina and medioventral carina strongly raised. Anterodorsal carina of protibiae raised, with 3–7 broad, triangular, lobe-like serrations. Posterodorsal carina with some small acute spines. Posterodorsal carina of mesofemora armed with 5–8 small saw-like spines; anterodorsal carina armed with 7–10 saw- to more prominent wave-shaped spines. Dorsal carinae of metafemora with 6–7 small saw-like spines. Medioventral of meso- and metafemora with 4–8 spines. Ventral carinae with 14–20 spine-like serrations. Ventral carinae of meso- and metatibiae serrated with small teeth. Dorsal carinae serrated with large to very large, roundly triangular pre-medial lobe; lobe more prominent on anterodorsal carina. Anterodorsal carina forming rounded, dentate lobe at apex of tibia. Probasitarsus with uniformly raised dorsal carina, about as long as remaining segments combined. Second tarsomere with dorsal carina raised and rounded. Meso- and metabasitarsus almost as long as remaining tarsomeres combined except claw and apically with dentate dorsal carina, gradually increasing in height.

Egg

Unknown.

Distribution ( Fig. 12 C )

This species is known from central Vietnam: Bach Ma National Park and Da Krong Nature Reserve.

Figures

Fig. 9. Phobaeticus trui sp. nov. — A–F. ♀. A. Habitus, dorsal view. B. Habitus, lateral view. C. Sternum VII and praeopercular organ. D. Mesofemur, lateral view. E. Apex of abdomen, lateral view. F. Apex of abdomen, dorsal view. — G–L. ♂. G. Habitus, dorsal view. H. Habitus, lateral view. I. Apex of abdomen, ventral view. J. Mesofemur, lateral view. K. Apex of abdomen, lateral view. L. Apex of abdomen, dorsal view. C–F, I–L = not to scale

Fig. 11. Photographs in natura by the authors. — A–B. Phryganistria heusii yentuensis subsp. nov. A. Mating pair. B. The first author with the 31.7 cm long ♀, Tay Yen Tu N.R., 9 Jul. 2013. — C–D. Phobaeticus trui sp. nov. C. ♂ and ♀, Bach Ma N.P., 13 Jul. 2013. D. ♂, Da Krong N.R., 7 Jul. 2011.

Fig. 12. Distribution maps. A. Phryganistria bachmaensis (Ta & Hoang, 2004) comb. nov. and P. heusii heusii (Hennemann & Conle, 1997). B. P. tamdaoensis sp. nov. and P. grandis Rehn, 1906. C. Phryganistria heusii yentuensis subsp. nov. and Phobaeticus trui sp. nov. D. Baculonistria magna (Brunner von Wattenwyl, 1907) comb. nov.