Orestes mouhotii ( Bates, 1865 )

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 : 45-51

Orestes mouhotii ( Bates, 1865)

Figs 5 , 23 D–F , 25–27

Acanthoderus mouhotii BATES, 1865: 342 [described].

Dares fulmeki WERNER, 1934: 81 [described]. Synonymised by BROCK (1998). Datames verruculatus REDTENBACHER, 1906: 222 [described]. Synonymised by ZOMPRO (2004).

Datames mouhotii – STÅL, 1875: 93 [transferred to Datames ]. — SHIRAKI, 1935: 25 [recorded in Taiwan and 2Japan]. — REDTENBACHER, 1906: 53 [redescription]. — BROCK, 1999: 138; fig 93a–c. [recorded in Malaysia, redescription, egg].

Orestes mouhotii – ZOMPRO & FRITZSCHE, 1999: 10 [transferred to Orestes ]. — BROCK, 2003: 70 [captive rearing]. — ZOMPRO, 2004: 222; fig. 132 a–b [redescription; description of male; senior synonym of Dares subcylindricus Redtenbacher, 1906 (error)]. — HO, 2013: 209; fig. 19 [recorded in China]. — SEOW- CHOEN, 2017: 131 [recorded in Singapore].

MATERIAL EXAMINED.

TYPE MATERIAL. THAILAND: HT ♀ nymph of Acanthoderus mouhotii Bates, 1865 (examined from photographs): Chantaboun, Mouhot (OUMNH).

INDONESIA, Sumatra: HT ♀ of Dares fulmeki Werner, 1934 (examined from photographs): Medan S.O.K.,I. Fulmek (NHMW).

THAILAND: HT ♀ nymph of Orestes verruculatus Redtenbacher, 1906 : Bangkok, Harmand, 1885 (MNHN).

ADDITIONAL MATERIAL. (12♂♂, 4 ♀♀, 1♂ nymph, 1 ♀ nymph, eggs): CAMBODIA: 8 ♂♂: Kampong Speu, Kirirom N.P., 11°18’37”N 104°03’04”E, night collecting/light trap, 9- 12.V.2015, leg. J. Constant & V. Sougnez, I.G.: 33.022 (6: RBINS; 2: RUPP); 4 ♀♀: same data, ex breeding Rob Krijns, 2017 (2 ♀♀: RBINS; 2 ♀♀: RUPP); 1 ♂: Koh Kong prov., Tatai, 11°35’13”N 103°05’50”E, leg. J. Constant & J. Bresseel, I.G.: 33.345 (RBINS); 1 ♀: Koh Kong prov., Tatai, 11°35’13”N 103°05’50”E, 7.VIII.2016, G. Chartier. I.G.: 33.345 (RBINS).

NOTES.

(1) The specimens attributed to O. mouhotii by SHIRAKI (1935) from Japan and Taiwan have been described as two distinct species, respectively Pylaemenes japonicus Ho, 2016 and P. shirakii Ho & Brock, 2013 ( HO, 2016; HO & BROCK, 2013).

(2) The occurrence of Orestes mouhotii ( Bates, 1865) from Malaysia and Singapore is doubtful as already pointed out by BROCK (1999) who stated that those records might represent a different species and that material from Cambodia is necessary for comparison. The synonymy with Dares fulmeki Werner, 1934 from Sumatra ( BROCK, 1998) is highly doubtful as well and needs verification. Therefore, records from Peninsular Malaysia, Singapore and Sumatra are omitted from the distribution map.

(3) Chantaboun is the former name of Chanthaburi (Chanthaburi Province, 12°36 ′ 31 ″ N, 102°6 ′ 14 ″ E), and is located in Thailand near the Cambodian border rather than in Cambodia as stated by BATES (1865).

(4) ZOMPRO (2004) synonymised Dares subcylindricus Redtenbacher, 1906 and Orestes verruculatus Redtenbacher, 1906 with O. mouhotii ( Bates, 1865) . The former here reinstated as a valid species infra and attributed to Orestes Redtenbacher, 1906 .

DIAGNOSIS. Strongly granulose and tuberculose species ( Figs 25 A , 26 A ).

Males can be separated from the other species of Orestes by the following combination of characters: antennae with 21 or 22 antennal segments (23 segments in other Orestes species); posterior margin of mesonotum with a pair of tubercles ( Fig. 25 I ); first antennomere slightly longer than pedicellus.

Females can be separated from the other species of Orestes by the following combination of characters: all cephalic armature except central coronal present as tubercles ( Fig. 26 I ); tergum IV indistinctly widening towards the posterior, almost parallel-sided ( Fig. 26 A ); metatibiae with dorsal, minute and conical teeth anteriorly and centrally; posteromedial crest on tergum IX not distinctly elongated but notched ( Fig. 26 E–F ).

DESCRIPTION

MALE ( Fig. 25 ).

Measurements: see table 7.

Head: supra-antennals spinose and slightly pointed outwards, followed by four spinose supraoccipitals. Vertex with anterior coronals distinctly enlarged, blunt and laterally compressed, creating ear-like processes. Supra-orbitals spinose. Posterior and lateral coronals present as small, elongated tubercles forming a corona with the apex of the postocular carina. Eyes relatively small, circular and strongly projecting hemispherically. Antennae shorter than legs with 21–22 segments (n = 6); scapus strongly flattened dorsoventrally and laterally carinate with a spine laterally and posterolaterally; pedicellus dorsoventrally flattened. First antennomere slightly longer than pedicellus. Antennomeres gradually getting longer till segment XII. Antennal segment XIII the longest, with minute hump anterolaterally; following segments shiny and distinctly shorter. Apical antennomere elongated, longer than the two preceding antennomeres combined.

Thorax: pronotum rugose, almost parallel-sided, slightly wider posteriorly, longer than wide. Anterior margin incurved. Prozona slightly elevated centrally with four granules. Metazona with four to six granules; posterior margin rounded. Mesonotum more or less parallel-sided with indistinct mediolongitudinal line, with anterior margin concave with a pair of granules; posteromedially with a pair of tubercles. Mesopleura slightly widened above coxae; widened portion rounded and notched medially. Metanotum more or less parallel-sided, posteromedially with two minute granules; posterior margin concave. Metapleura widened above coxae, and rounded and notched posterolaterally. Prosternum with sensory areas elongate oval. Sensory area on profurcasternum small and subcircular. Ventral surface of body rugose.

Legs: profemora unarmed, curved basally with carinae rather indistinct with anterodorsal carinae more distinct; posterior margin with small tubercle; almost as long as metanotum, median segment and tergum II combined. Mesofemora unarmed with carinae indistinct; only slightly shorter than profemora, slightly longer than metanotum and median segment combined. Metafemora about as long as profemora, shaped like mesofemora; dorsally with a small blunt tooth subcentrally. Protibiae unarmed, slightly shorter than profemora. Meso- and metatibiae with carinae indistinct, slightly shorter than corresponding femora and unarmed. Tarsomeres I–III about the same length with a posteromedian rounded hump dorsally. Claws very small.

Abdomen: median segment rugose, strongly transverse and with a pair of minute granules posteromedially. Abdominal terga rugose; terga II–V about the same length; tergum VI slightly shorter; tergum II almost quadrate, slightly narrowing towards the posterior; terga III– VII posteromedially parallel-sided, unarmed or sometimes armed with two minute granules posteromedially; posterior margin of tergum VII concave; tergum VIII wider than VII, trapezoidal and widening towards the posterior, with posterior margin concave; IX about as long as VIII, almost quadrate, with posterior margin with small hump posteromedially. Anal segment dorsoventrally flattened, parallel-sided and notched posteromedially. Posterolateral angles broadly rounded. Poculum more or less rounded and strongly granulose; posterior rim dorsoventrally flattened, thickened and broadly rounded posteriorly. Poculum projecting over base of vomer and 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, strongly upcurving with an angle of almost 90°.

FEMALE ( Fig. 26 ).

Measurements: see table 7.

Head: complete armature except central coronal present as tubercles, supra-antennals slightly larger and conical. Vertex not elongated or raised but slightly rounded. Posterior and lateral coronals distinct as stalked tubercles. Behind eye, a distinct carina reaching posterior edge of crest, resulting in an elongated tubercle. Eyes relatively small, circular and strongly projecting hemispherically. Antennae slightly shorter than legs with 24 segments (n = 4); scapus strongly flattened dorsoventrally, laterally carinate and with a central tubercle and subapical spine on the outer lateral carina; pedicellus slightly dorsoventrally flattened, slightly narrowing towards the posterior. First antennomere about as long as the following three antennomeres combined; antennal segment IV to XV gradually becoming longer. Segment XV with a minute spine anterolaterally, following segments shorter than XV except for apical antennomere which is elongated and club-shaped.

Thorax: pronotum trapezoidal, widening towards the posterior; anterior margin strongly convex; prozona with a pair of granules antero- and posteromedially; metazona with two longitudinal rows of 3 granules; lateral margin with four evenly spaced granules. Mesonotum rugose with anterior margin thickened, strongly incurved and with two distinct granules anteromedially; sublateral margins with few evenly spaced granules; posterior margin wider than anterior margin. Between lateral margin and median line, a row of evenly spaced granules almost parallel to lateral margin. Posterior margin with a pair of transversely elongated granules. Posterior margin slightly concave. Mesopleura slightly widened above coxae; widened portion with lateral margins crenulated, anterior portion with some raised granules. Metanotum more or less parallel-sided, armature more or less as in mesonotum. Metapleura widened above coxae, anterior portion with few small tubercles, posterior portion rounded with posterolateral notch. Prosternum with sensory areas elongate oval, not reaching lateral margins. Sensory area on profurcasternum small and rounded, anterior margin more or less straight. Meso- and metasternum with two longitudinal rows of distinct granules.

Legs: femora with carinae relatively indistinct except for anterodorsal carina of profemora which is laterally compressed and raised; apex with small granule. Profemora rugose, shorter than mesonotum and curved basally. Mesofemora about as long as metanotum and median segment combined and with some indistinct humps dorsally. Metafemora about as long as profemora with a dorsal conical tooth subcentrally and a granule in the posterior half. Tibiae shorter than corresponding femora. Protibiae carinate and unarmed. Mesotibiae unarmed. Metatibiae with some indistinct granules dorsally. Tarsomeres I-III about the same length with a rounded hump dorsally, IV distinctly shorter. Claws very small.

Abdomen: Median segment rugose, strongly transverse and with posterior margin more or less straight. Abdominal terga rugose; terga II–IV slightly widening gradually towards the posterior; II–III with indistinct mediologitudinal carina, distinctly granulose between carina and lateral margin, medially and posterolaterally with small granule; tergum IV with a posterolateral triangular tubercle; posteromedially with a twin-crescent-shaped crest, granules as in III; tergum V slightly descending obliquely with posterior margin slightly narrower than anterior one, armature as IV but posteriorly with flattened triangular tubercles; triangular tubercles projecting over posterior margin; tergum VI distinctly descending and granulose, with posterior margin distinctly narrower than anterior one and incurved; tergum VII almost parallel-sided, slightly tapering towards the posterior with a mediolongitudinal carina and incurved posteriorly; tergum VIII more or less parallel-sided, slightly ascending and strongly granulose; posterolaterally with a triangular granule and posteromedially with a pair of minute, raised granules; IX about as wide as VIII with a posteromedial crest, crest pointed more or less upwards and notched apically; posterolateral margins rounded and with several granules. Anal segment narrower than tergum IX and dorsally flattened; anteriorly with a tubercle medially, posteromedially with apair of granules; sublaterally with an oblique, compound and lamellate carina continuing on posterolateral angles; posterolateral angles lamellate and raised. Subgenital plate with a mediolongitudinal carina; rounded and boatshaped with widest part at about mid length; posterior rim dorsoventrally flattened; apex more or less rounded, almost reaching margin of tergum X.

EGG ( Fig. 23 D–F ) [ex. breeding O.P.I.E. 22.I.2014, origin: Thailand].

Measurements [mm]. Length: 3.6; width: 2.5; height: 3.1.

Egg capsule subspherical, slightly compressed laterally and brown. Capsule covered with minute pits. Operculum subcircular, slightly convex. Capsule and operculum covered with long setae 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 distinctly widening towards the capsule. Anterior margin almost straight, reaching edge of capsule. Posterior arms ax-shaped, laterally directed and projecting on lateral surface of capsule but not reaching ventral side. Margin of micropylar plate darker and indistinctly raised. Micropylar cup small, black, cup-shaped and protruding.

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. 25. Orestes mouhotii (Bates, 1865), ♂ from Cambodia, Kirirom 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, lateralview. H, terminalia,ventral view. I, head and thorax,lateral view.

Fig. 26. Orestes mouhotii (Bates, 1865), ♀ from Cambodia, Tatai. A, habitus, dorsal view. B, habitus, ventral view. C, head and thorax, dorsal view. D, terminalia, dorsal view. E, terminalia anterodorsal view. F, terminalia, lateralview.G, habitus lateralview.H, terminalia, ventral view. I, head and thorax,lateral view.

Fig. 27. Orestes mouhotii (Bates, 1865), in nature. A–D, Cambodia, Tatai (photographsby G.Chartier).A, adult male, 12.X.2016. B, adult male, 17.V.2015. C, mating pair, 5.II.2017. D, female subadult nymph. E–H, Cambodia,Kirirom N.P., 11.V.2015. E–F, adult male.G, adult female. H, adult pair.

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