Orestes subcylindricus ( Redtenbacher, 1906 ) Joachim Bresseel & Jérôme Constant, 2018

Joachim Bresseel & Jérôme Constant, 2018, The Oriental stick insect genus Orestes Redtenbacher, 1906: Taxonomical notes and six new species from Vietnam (Phasmida: Heteropterygidae: Dataminae), Belgian Journal of Entomology 58, pp. 1-62 : 52-59

Orestes subcylindricus ( Redtenbacher, 1906) stat. rev., comb. nov.

: urn:lsid:zoobank.org:act:EFD5D814-3F88-4D8E-9718-24EC70AF0DFE Figs 5 , 23 G–I , 28–31

Dares (Dares) subcylindricus REDTENBACHER, 1906 : 56 [described].

Dares (Dares) subcylindricus – BRAGG, 1998: 60 [type identified as female nymph]. — BROCK, 1998: 61 [catalogued]. — BRAGG, 2001: 147 [type identified as female nymph]. — ZOMPRO, 2004: 222 [synonymised with O. mouhotii ( Bates, 1865) in error].

MATERIAL EXAMINED.

TYPE MATERIAL. VIETNAM: holotype: subadult ♀ (examined from photographs): Tonkin, Montes Mauson , April-Mai, 2-3000, H. Fruhstorfer; 24.316 ( NMW, No. 55).

ADDITIONAL MATERIAL. (25♂♂, 20 ♀♀, 2 ♀♀ nymphs, eggs): VIETNAM: 9♂♂, 10 ♀♀, 2 ♀♀ nymphs, eggs: Ninh Binh prov., Cuc Phuong Nat. Park, 20°20’53”N105°35’52”E, 31.VII- 3.VIII.2016, GTI Project, Leg. J. Constant & J. Bresseel, I.G.: 33.282 (7♂♂, 8 ♀♀, 2 ♀♀ nymphs, eggs: RBINS; 2♂♂, 2 ♀♀: VNMN); 6♂♂, 4 ♀♀: Cuc Phuong N. P., 20°19’00”N105°36’30”E, 19-23.VII.2011, Leg. J. Constant & J. Bresseel, I.G.: 31.933 (4♂♂, 2 ♀♀: RBINS; 2♂♂, 2 ♀♀: VNMN); 3♂♂, 3 ♀♀: Hoa Binh prov., Ngo Luong Nat. Res., 20°26’16”N105°20’15”E, 25-30.VII.2016, GTI Project, Leg. J. Constant & J. Bresseel, I.G.: 33.282 (2♂♂, 2 ♀♀: RBINS; 2♂♂, 1 ♀: VNMN); 2♂♂, 1 ♀: Tay Yen Tu Nat. Res., 21°11’10”N 106°43’25”E, 7-11.VII.2013, night collecting, leg. J. Constant & J. Bresseel, I.G.: 32.454 (1♂, 1 ♀: RBINS; 1♂: VNMN); 1♂: Vietnam: Cuc Phuong, 11-18.VII.2010, I.G.: 31.668, Leg J. Constant & P. Limbourg (RBINS); 1♂: Ex breeding Rob Krijns 2017, origin: Cuc Phuong N.P., 20°19’00”N105°36’30”E, VII.2011, J. Constant & J. Bresseel, I.G.: 32.387 (RBINS); 1 ♀: Ex breeding Rob Krijns 2012, origin: Cuc Phuong N.P., 20°19’00”N 105°36’30”E, VII.2011, J. Constant & J. Bresseel, I.G.: 32.387 (RBINS); 1 ♂: Tonkin, reg. de Hoa Binh, 1927, A. De Cooman (MNHN).

DIAGNOSIS. Relatively large species with strongly lamellate cephalic crest ( Figs 28 I , 29 I , 30 I ). Males have tergum IV posteromedially raised and armed with two distinct tubercles ( Figs 28 B , 29 B ). Females have the leg armature well developed, abdominal terga IV–V almost parallel-sided ( Fig. 30 A ) and the posteromedian crest on tergum IX distinctly notched ( Fig. 30 D ).

DESCRIPTION.

MALE ( Figs 28–29 ).

Measurements: see table 8.

Head: supra-antennals spinose and slightly pointed outwards followed by four smaller supraoccipitals, the anterior being the smallest. Vertex raised, supra-orbitals laterally compressed, triangular. Anterior coronals strongly compressed laterally and lamellate, about as high as supra-orbitals. Central coronal conical, about as long as posterior coronals. Posterior and lateral coronals present as small, conical tubercles. Behind eyes, a distinct carina reaching posterior edge of crest resulting in a conical tubercle. Eyes relatively small, circular and strongly projecting hemispherically. Antennae shorter than legs, with 23 segments (n = 10); scapus strongly flattened dorsoventrally and laterally carinated with a spine laterally and posterolaterally; pedicellus slightly flattened dorsoventrally, narrowing towards the posterior. First antennomere distinctly longer than pedicellus. Antennomeres gradually getting longer till segment XII. Antennal segment XIII about the same length as XII, with minute spine anterolaterally; following segments shiny and distinctly shorter. Apical antennomere elongated, club-shaped.

Thorax: pronotum more or less parallel-sided, indistinctly wider posteriorly, almost quadrate and rugose. Anterior margin incurved. Prozona with slight elevation centrally with four tubercles; anterior tubercles slightly larger. Metazona with a pair of granules anteriorly and posteriorly. Mesonotum rugose with anterior margin thickened, distinctly concave and with a pair of minute granules anteromedially. Posterior portion slightly wider, posteromedially with a pair of minute granules. Mesopleura widened above coxae; widened portion rounded and indistincly notched medially. Metanotum more or less parallel-sided, rugose and unarmed. Metapleura widened above coxae, rounded and slightly crenulated. Prosternum with sensory areas elongate oval. Sensory area on profurcasternum small and circular.

Legs: femora with carinae relatively indistinct except for the anterolateral carina of the profemora, with dorsal posterior margin with short spinose tubercle. Profemora about as long as mesonotum, curved basally and unarmed. Mesofemora about as long as metathorax, dorsally with a blunt tubercle centrally and subapically; outer ventral carina with one, sometimes two granules subapically. Metafemora about as long as profemora; ventrally armed as mesofemora; dorsally with a definite blunt tooth centrally and subapically. Tibiae with carinae indistinct, slightly than shorter corresponding femora; dorsally with a blunt tooth centrally, slightly larger on mesotibiae and even more so on metatibiae. Tarsomeres I–III about the same length with a posteromedian rounded hump dorsally. Claws very small.

Abdomen: median segment unarmed and rugose, with posterior margin slightly concave. Abdominal terga rugose, only slightly varying in length; tergum II transverse, slightly narrowing towards the posterior; tergum IV and sometimes V posteromedially raised and armed with two tubercles; terga VI–VIII with two posteromedian granules; tergum VIII slightly wider than VII, widening towards the posterior and with posterior margin concave; IX distinctly transverse, with posterior margin with minute posteromedian ridge. Anal segment narrower than IX, dorsoventrally flattened, almost parallel-sided and indistinctly notched posteromedially. Posterolateral angles rounded. Poculum triangular from lateral view and strongly granulose; posterior rim dorsoventrally flattened and minutely notched posteriorly, posterolateral angles broadly rounded. Poculum projecting over base of vomer but not reaching base of apical spine. Cerci short, strongly flattened and setose, not reaching apex of tergum X, with apices broadly rounded to almost straight. Vomer well developed, semicircular basally till base of posteromedial spine; posteromedial spine broad and blackish in posterior portion; apex curved, not ending medially. Ventral surface of body rugose.

FEMALE ( Fig. 30 ).

Measurements: see table 8.

Head: supra-antennals short and conical. Anterior supra-occipitals present as small conical humps, posterior supra-occipitals smaller. Vertex distinctly raised, supra-orbitals strong, laterally compressed and lamellate. Anterior coronals laterally compressed and lamellate, directing towards supra-orbitals. Central coronal only present as small granule. Posterior and lateral coronals present as conical tubercles. Between lateral coronal and supra-orbital, a row of tubercles; between lateral and anterior coronal several tubercles on side of crest. Postocular carina distinct, apex as triangular tubercle. Eyes relatively small, circular and strongly projecting hemispherically. Antennae shorter than legs, with 25 segments (n = 10); scapus strongly flattened dorsally and laterally carinated, with a definite spine posterolaterally mediolaterally; pedicellus slightly flattened dorsoventrally, laterally carinate. First antennomere longer than the following three antennomeres combined. Apical antennomere elongated and club-shaped.

Thorax: pronotum trapezoidal, slightly widening towards the posterior; lateral margins rugose and slightly concave, anterior margin incurved. Prozona with distinct elevation centrally with four granules; metazona with three pairs of granules, posterior margin straight. Mesonotum rugose, indistinctly widening towards the posterior; anterior margin thickened with some granules; sublaterally with two rows of distinct humps. Mesopleura slightly widened above coxae; widened portion notched medially and armed with few granules. Metanotum as mesonotum. Metapleura as mesopleura but posterolaterally notched. Prosternum with sensory areas elongate oval. Sensory area on profurcasternum small and circular. Meso- and metasternum with several enlarged black granules.

Legs: profemora about as long as mesonotum and curved basally, with some minute humps on dorsal carina; exteroventral carina with some evenly spaced minute granules. Mesofemora shorter than mesonotum; externodorsal carina with three flattened and apically rounded teeth, distal one stronger; inner dorsal carina with three to four minute humps. Medioventral carina indistinct. Outer ventral carinae with two pairs of granules or small teeth posteriorly; anteriorly with few indistinct granules. Metafemora about as long as profemora; armed as mesofemora. Tibiae slightly shorter than corresponding femora. Protibiae with three to four laterally compressed humps on dorsal carinae, central armature more distinct. Meso- and metatibiae with a distinct, laterally compressed and rounded lobe dorsally, ventrally unarmed. Tarsomeres I–III about the same length with a posteromedian rounded hump dorsally; IV distinctly shorter. Claws very small.

Abdomen: median segment rugose, unarmed, strongly transverse and with posterior margin almost straight. Abdominal terga rugose; terga II–VIII with X-shaped carina medially; terga II–IV gradually widening towards the posterior; terga III–V with a distinct triangular process posterolaterally; terga IV and V almost parallel-sided and slightly notched posteromedially; posterior margin raised and tuberculose; posterior margin of tergum V projecting over anterior margin tergum of VI; tergum VI distinctly narrowing towards the posterior and strongly descending, with posterior margin slightly concave; tergum VII slightly narrowing towards the posterior, slightly longer than previous one; tergum VIII parallel-sided and slightly ascending; posterolateral angles with distinct tubercle and posteromedially with at least one pair of granules; IX slightly triangular, tapering towards the posterior, only slightly projecting over anal segment; posteromedially tectiform and notched; sublaterally with an oblique row of granules. Anal segment narrower and shorter than tergum IX, obliquely descending and dorsally flattened with outer margin lamellate; anteriorly with a tubercle medially; oblique carinae lamellate; posterior margin relatively straight, slightly crenulated to indistinctly notched. Abdominal sterna and subgenital plate with a mediolongitudinal carina.

Sterna with a pair of granules anteriorly and posteromedially; praeopercular organ knob-like and slightly flattened laterally. Subgenital plate rugose, boat-shaped with widest part at about mid length; posterior rim dorsoventrally flattened and rounded posteriorly; laterally with two rows of granules. Apex broadly rounded, almost reaching margin of tergum X.

EGG ( Fig. 23 G–I ).

Measurements [mm]. Length: 4.0; width: 3.1; height: 3.5.

Egg capsule subspherical and brown. Capsule covered with minute pits. Operculum subcircular, slightly convex. Capsule and operculum covered with long setae (about 0.3 mm) with a distal black two to four-hooked grapnel-shaped structure. Base of long setae surrounded by very short hairs, creating small circular patches on capsule and operculum. Micropylar plate trilobate with one anterior expansion and with two posterior expansions. Anterior expansion slightly widening towards the capsule. Anterior margin almost reaching edge of capsule. Posterior arms directed laterally and almost completely circling polar area,

but not touching each other on ventral side. Posterior arms dilated laterally on capsule, projecting over half the capsule length. Margin of micropylar plate indistinctly raised and demarcated by more dense setae. Micropylar cup small, black, cup-shaped and protruding.

NOTE. Males from Cuc Phuong N.P. and Ngoc Son-Ngo Luong N.R have only tergum IV posteromedially raised and armed with two distinct tubercles ( Fig. 28 B ) while males from Tay Yen Tu N.R. have also tergum V with two distinct tubercles ( Fig. 29 B ).

* After RETDENBACHER (1906). ** Anterior part of median segment fused with metanotum.

Figures

Fig. 23. Orestes spp., eggs. A–C, O. krijnsi sp. nov. A, lateral view. B, dorsal view. C, operculum. D–F, O. mouhotii (Bates, 1865) (photographs by F. Tetaert). D, lateral view. E, dorsal view. F, operculum. G–I, O. subcylindricus(Redtenbacher,1906)comb. nov. G, lateral view. H, dorsalview. I, operculum.

Fig.5. Orestes. spp., distribution map.

Fig.28. Orestes subcylindricus (Redtenbacher, 1906)comb. nov., ♂ fromVietnam, Cuc Phuong N.P. A, habitus, dorsal view. B, habitus, lateral view. C, habitus, ventral view. D, head and thorax, dorsal view. E, terminalia, dorsal view. F, terminalia anterodorsal view. G, terminalia, ventral view. H, terminalia, lateral view. I, head and thorax, lateralview.

Fig.29. Orestes subcylindricus (Redtenbacher, 1906) comb. nov., ♂ fromVietnam,Tay Yen Tu N.R. A, habitus, dorsal view. B, habitus, lateral view. C, habitus, ventral view. D, head and thorax, dorsal view. E, terminalia, dorsal view. F, terminalia anterodorsal view. G, terminalia, ventral view. H, terminalia, lateral view. I, head and thorax, lateralview.

Fig.30. Orestes subcylindricus (Redtenbacher, 1906)comb. nov., ♀ fromVietnam, Cuc Phuong N.P. A, habitus, dorsal view. B, habitus, ventral view. C, head and thorax, dorsal view. D, terminalia, dorsal view. E, terminalia anterodorsal view. F, terminalia, lateral view. G, habitus, lateral view. H, terminalia, ventral view. I, head and thorax, lateralview.

Fig. 31. Orestes subcylindricus (Redtenbacher, 1906) comb. nov., in nature. A–C, Vietnam, Cuc Phuong N.P., 20-22.VII.2011. A, adult male. B, adult female. C, adult female. D–E, Vietnam, Ngoc Son-Ngo Luong N.R., 25- 30.VII.2016. D, subadult female. E, mating pair.