Phryganistria heusii yentuensis, 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 : 23-27

Phryganistria heusii yentuensis subsp. nov.

urn:lsid:zoobank.org:act:CDA37092-5410-4797-A155-85327D3E2A3B

Figs 8A–N , 11A–B

Diagnosis

Males can be distinguished from all other members of the genus by the combination of the following characters: profemora black, meso- and metapleura with distinct triangular black marking and shape of the semitergites ( Fig. 8K, M–N ); females: tergites II–VII with a posteromedian granule and praeopercular organ of female wide and not strongly tapered ( Fig. 8C ).

Etymology

The subspecies name refers to its type locality: the Tay Yen Tu Nature Reserve.

Type material

Holotype

VIETNAM: ♂, Tay Yen Tu Nat. Res., 21°11’10” N, 106°43’25” E, 7–11 Jul. 2013, leg. J.Constant & J. Bresseel, I.G. 32.454 ( RBINS).

Paratypes (10 ♂♂, 7 ♀♀, 20 eggs)

VIETNAM: Tay Yen Tu Nat. Res., 21°11’10” N, 106°43’25” E, 7–11 Jul. 2013, leg. J. Constant & J. Bresseel, I.G. 32.454 ( RBINS; 1 ♂, 1 ♀: VNMN).

Additional material examined

VIETNAM: 1 ♂, paralectotype of Phobaeticus fruhstorferi Brunner von Wattenwyl, 1907 , Tonkin, Montes Mauson, April–May, 2–3000 m, H. Fruhstorfer ( NMW). Specimen examined from detailed photographs in the Phasmida Species File ( Brock 2014).

Description

The colouration is described from photographs of live specimens. Measurements, see Table 3.

Male ( Fig. 8I–N )

BODY. Large and relatively slender.

COLOURATION. Body surface smooth and glabrous, colouration characteristic. Overall colouration of body orange-brownish to light brown. Genae black. Distal portions of meso- and metapleura with distinct triangular black marking. Profemora basally as body, followed by large black portion, apex brown. Protibiae and tarsi blackish brown with a dark reddish hue. Meso- and metafemora coloured as body, ventral carinae with faint blue colouration. Armature black. Meso- and metatibiae coloured as femora except for blue markings.

HEAD. Smooth, 1.3x longer than wide, widest parts at eyes. Eyes relatively large and strongly projecting hemispherically. Small, shallow transverse sulcus between antennae. Vertex with faint median line, lateral edges of vertex with longitudinal depression, more distinct posteriorly. Antennae long and filiform, scapus and pedicellus coloured as head, all other antennomeres black. Scapus dorsoventrally flattened, pedicellus short and swollen, broader than following segments.

* mesonotum of all females deformed during drying process

THORAX. Pronotum shorter and narrower than head. Anterior margin concave. Pronotum gradually broadening until about 2/3 of its length, remaining portion parallel-sided. Posterior margin rounded, with minute, granule-like elevation postero-medially. Transverse central depression and faint longitudinal depression, not reaching posterior margin. Mesonotum elongated and smooth, cylindrical in cross section. Metanotum as mesonotum, about 4x length of median segment.

ABDOMEN. Median segment trapezoidal and smooth, anterior margin indistinct. Terga II–VI becoming slightly longer and cylindrical in cross section. Segment VI about 1.3 to 1.4x as long as segment VII. Tergum VIII trapezoidal, about half of segment VII and wider posteriorly. Tergum IX shorter than VIII. Anal segment strongly tectiform basally, splitting into two semi-tergites. Semi-tergites elongated, relatively slender and tapered apically. Apices narrow and slightly rounded. Interior surface swollen basally and armed with numerous small, black, back-curving teeth. Outer surface setose. Cerci elongated, cylindrical in cross section, setose and incurving. Apices rounded, not reaching posterior margin of anal segment. Poculum strongly cup-shaped, with indistinct longitudinal carina in basal half, medially with V-like elevation, connecting distinct longitudinal carina in apical half with transverse ridges, roughly reaching apex of tergum IX.

LEGS. Profemora longer than combined length of head, pro- and mesonotum, incurving basally and with anterodorsal carinae showing 12–19 black saw-like teeth. Protibiae carinate but unarmed, roughly 1.3x as long as profemora. Mesofemora swollen, about as wide as centre of mesonotum and roughly as long as mesonotum and pronotum combined. Outer ventral carinae armed with 10–15 black sawlike teeth, last teeth prominently enlarged, in some specimens last two teeth of carina enlarged. Medioventral carinae sometimes with few minute spines. Dorsal carinae unarmed or with 1–3 saw-like teeth. Mesotibiae slightly longer than mesofemora. Dorsal carinae unarmed or with few minute teeth. Outer ventral carinae strongly armed with saw-like teeth. Medioventral carinae with minute incurving spines starting at about 1/3 of the base, spines more numerous towards apex. Metafemora and metatibiae as mesofemora and mesotibiae. All tarsomeres with distinct dorsal carina. Probasitarsus longer than the following tarsomeres combined. Meso- and metabasitarsus about as long as following tarsomeres combined. Claws prominent.

Female ( Fig 8A–F )

BODY. Large to very large. Colouration of female green to brown. Basal curve of profemora pinkish.

HEAD. Oval, about 1.4–1.5x longer than wide, vertex rounded. Transverse, straight impression between bases of antennae. Eyes quite large, circular and convex. Antennae filiform with scapus dorsoventrally flattened, rectangular and slightly widening towards apex. Pedicellus short and cylindrical. Antennomere III about as long as pedicellus. Antennae projecting well over posterior margin of mesonotum.

THORAX. As in male.

ABDOMEN. Median segment transverse, but longer than wide in the largest specimen. Segments II–VI slightly increasing in length, all having a posteromedian tubercle. Tergum VII shorter than VI and with posterolateral small, rounded lobe. Sternum VII with distinct praeopercular organ at posterior margin. Praeopercular organ formed by a pair of rounded lobe-like protuberances, rounded laterally and wrinkled ventrally; projecting over margin of sternum VIII. Tergum VIII distinctly narrower than previous one, laterally compressed and about half as long as V. IX roughly half as long as VIII. Anal segment slightly longer than IX, with faint median carina and almost triangular median incision at posterior margin. Posterolateral angles rounded apically. Supra-anal plate small, semi-circular and with distinct median carina, slightly surpassing anal segment. Cerci flattened, slender and blunt at apex, projecting over supra-anal plate. Gonapophyses elongated, up-curving and slightly projecting over apex of subgenital plate. Subgenital plate keeled, boat-shaped, surpassing apex of anal segment.

LEGS. All moderately long and robust. Profemora longer than pro- and mesonotum combined; mesofemora as long as mesotibiae; metafemora reaching about halfway along abdominal segment V. Anterodorsal and posteroventral carinae of profemora armed with 13–19 prominent, triangular serrations. Posterodorsal carinae unarmed or armed with 1–3 minute spines. Other carinae unarmed. Protibiae carinate, roughly 1.3x as long as profemora, posteroventral carinae serrated with saw-like spines. Mesofemora swollen and roughly as long as mesotibiae. Outer ventral carinae armed with 13–18 saw-like teeth. Medioventral carina with 6–9 spines. Dorsal carinae with 1–4 saw-like teeth, being larger on anterodorsal carinae. Mesotibiae with strongly serrated ventral carinae. Anteroventral carinae with few small spines and enlarged saw-like spine at about 1/3 of its length. Posterodorsal carinae with few minute spines. Metafemora and metatibiae as mesofemora and mesotibiae. All tarsomeres with distinct dorsal carina. Probasitarsus longer than following tarsomeres combined. Meso- and metabasitarsus with outer ventral carinae serrated basally, about as long as following tarsomeres combined. Claws prominent.

Egg ( Fig. 8G–H )

Capsule oval in lateral aspect, rounded at polar area, slightly compressed laterally and oval in crosssection. Capsule with indistinct impression on polar area and ventral surface. Capsule surface smooth and slightly shining. General colouration of capsule and micropylar plate light brown to grey brown, sometimes with blakish areas. Operculum oval, brownish with black outer margin. Micropylar plate covering about half capsule length. Elongate, rounded towards anterior end and posteromedially with distinct gap. Posterolateral angles rounded. Outer margin dark. Micropylar cup small and dark brown, placed in posteromedial gap of plate. Median line distinctly projecting over posterior margin of plate. Capitulum enlarged, orange to reddish brown, irregularly conical and strongly wrinkled. Stalk obvious.

Measurements (mm): length including capitulum: 6.0, length: 5.0, width: 3.6, height: 4.0.

Differentiation

Males share the black profemora and tibiae with the nominate form, but can easily be distinguished by the brown body colouration and meso- and metapleura with distinct triangular black marking. Apices of praeopercular organ of female wider but not as strongly tapered when compared with Ph. heusii heusii . Micropylar plate of egg rounded anteriorly (tapered in nominal form) and capitulum strongly enlarged.

Remarks

Hennemann & Conle (2008: 204) stated that the three male paralectotypes of Phryganistria fruhstorferi (Brunner von Wattenwyl, 1907) in NMW represent males of Phryganistria grandis Rehn, 1906 . However, one of these paralectotypes has turned out to be a Phryganistria heusii yentuensis subsp. nov. The male originates from Mount Mauson (misspelled on the original label as ‘Montes Mahokon’).

Hennemann & Conle (2008) examined a large amount of non-type material of Phryganistria grandis , but only this specimen originates from Mount Mauson.

Eggs of this subspecies have been collected from Tay Yen Tu Nature Reserve and it is currently reared by Dr. Bruno Kneubühler ( Switzerland) with bramble ( Rubus spp., Rosaceae ) as alternative foodplant.

P. heusii yentuensis subsp. nov. is the second longest insect species known to date: a female with a 320.0 mm body length, 540.0 mm with anterior legs spread ( Fig. 11A–B ) was captured and measured in the field.

Distribution ( Fig. 12C )

This subspecies is currently recorded from Tay Yen Tu Nature Reserve located in Luc Nam and Son Dong Districts, Bac Giang Province, about 150 kilometers ENE of Hanoi. Another specimen is also reported from northeast Vietnam: Mount Mauson, 30 km E of Lang Son city.

Figures

Fig. 8. Phryganistria heusii yentuensis subsp. 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–H. Egg. G. Lateral view. H. Dorsal view. — I–N. ♂. I. Habitus, dorsal view. J. Habitus, lateral view. K. Apex of abdomen, ventral view. L. Mesofemur, lateral view. M. Apex of abdomen, lateral view. N. Apex of abdomen, dorsal view. C–H, K–N = 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.