Orestes dittmari, 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 : 28-33

publication ID

https://doi.org/ 10.5281/zenodo.1162066

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scientific name

Orestes dittmari

sp. nov.

Orestes dittmari View in CoL sp. nov.


Figs 5 View Fig.5 , 8 D–F View Fig.8 , 15–17 View Fig. 15 View Fig. 16 View Fig. 17

ETYMOLOGY. The species is named after Mr Daniel Dittmar (Germany) in acknowledgement for breeding several stick insect species that we brought back from Southeast Asia.

TYPE MATERIAL. VIETNAM. Holotype ♂: Vietnam, Cat Ba N.P. , 20°48’00”N 107°00’20”E, 12-16.VII.2013, leg. J. Constant & J. Bresseel, I.G.: 32.454 ( RBINS). GoogleMaps

Paratypes (1 ♀, 2 eggs): 1 ♀: same data as HT (RBINS). GoogleMaps

DIAGNOSIS. Males have the mesonotum distinctly elevated posteriorly ( Fig. 15 I View Fig. 15 ); the cephalic armature is not fused, the anterior coronals are laterally compressed and rounded apically ( Fig. 15 I View Fig. 15 ).

Females have a low crest on the head ( Fig. 16 I View Fig. 16 ); the body armature is never acute and the abdomen is distinctly dilated laterally ( Fig. 16 A View Fig. 16 ).


MALE ( Fig. 15 View Fig. 15 ).

Measurements: see table 4.

Head: supra-antennals strongly spinose and slightly pointed outwards, about as long as supraorbitals; supra-occipitals smaller, the posterior being the smallest. Vertex raised; supraorbitals strong, conical and spinose. Anterior coronals strongly flattened laterally and rounded apically. Central coronal conical, slightly longer than posterior coronals. Posterior and lateral coronals present as small, conical tubercles. Behind eye, 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 = 1); scapus strongly flattened dorsally, laterally carinated and with a spine laterally and posterolaterally; pedicellus slightly flattened dorsoventrally, narrowing towards the posterior. First antennomere about as long as pedicellus. Antennomeres gradually getting longer till segment XIII. Antennal segment XIII the longest, with minute granule anterolaterally; following segments shiny and distinctly shorter. Apical antennomere elongated, club-shaped.

Thorax: pronotum rugose, more or less parallel-sided, indistinctly wider posteriorly; almost quadrate with anterior margin incurved. Prozona with central elevation with four tubercles; anterior tubercles slightly larger. Metazona slightly lower than prozona, and with three pairs of granules. Mesonotum rugose with anterior margin thickened, distinctly concave and with a pair of minute granules anteromedially; posterior portion slightly raised anterolaterally and distinctly conically raised posteromedially; posteromedial elevation indistinctly V-shaped and sulcate centrally. Mesopleura widened above coxae; widened portion rounded, slightly crenulated and indistinctly notched medially. Metanotum more or less parallel-sided, rugose and slightly raised posterolaterally. Metapleura widened above coxae, rounded and slightly crenulated. Prosternum with sensory areas elongate oval. Sensory area on profurcasternum small and circular. Ventral surface rugose.

Legs: femora with carinae relatively indistinct except for the anterolateral carina of the profemora, dorsal posterior margin with indistinct triangular tubercle. Profemora slightly shorter than mesonotum, curved basally and unarmed. Mesofemora about as long metanotum and median segment combined with some indistinct granules; outer ventral carina with 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 relatively indistinct, slightly shorter than corresponding femora; dorsally with some indistinct granules. Tarsomeres I–III about the same length with a posteromedian rounded hump dorsally. Claws very small.

Abdomen: median segment unarmed and rugose, indistinctly raised medially. Abdominal terga rugose; terga II–VI about the same length; tergum II transverse, slightly narrowing towards the posterior; terga III–VII parallel-sided; II–VIII with a pair of minute granules posteromedially; tergum VII slightly shorter than VI; tergum VIII slightly wider than VII, transverse and widening towards the posterior, with posterior margin concave; IX distinctly transverse, with posterior margin with posteromedian ridge, raised apically. Anal segment narrower than tergum IX, dorsoventrally flattened, almost parallel-sided and indistinctly concave posteromedially; posterolateral angles rounded and medially with a transverse row of three granules and laterally a larger granule in middle. Poculum rounded and strongly granulose; posterior rim dorsoventrally flattened and broadly rounded anteriorly. 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 the posterior portion and with apex curved.

FEMALE ( Fig. 16 View Fig. 16 ).

Measurements: see table 4.

Head: supra-antennals short, conical and blunt. Anterior supra-occipitals present as small conical humps, posterior supra-occipitals smaller and granulose. Vertex indistinctly raised, supra-orbitals short, laterally compressed and rounded apically. Anterior coronals fused with supra orbitals, laterally compressed and lamellate. Central coronal indistinct, only present as small granule. Posterior and lateral coronals present as conical tubercles. Postocular carina distinct, apex as triangular tubercle. Eyes relatively small, circular and strongly projecting hemispherically. Antennae shorter than legs and with 25 segments (n = 1); scapus strongly flattened dorsally and laterally carinated, with a definite spine posterolaterally and a shorter spine mediolaterally; pedicellus slightly flattened dorsoventrally, slightly narrowing towards the posterior. First antennomere longer than the following two antennomeres combined. Apical antennomere elongated and club-shaped.

Thorax: pronotum trapezoidal, slightly widening towards the posterior; lateral margins rugose, anterior margin incurved. Prozona with distinct elevation centrally with four granules. Metazona with some indistinct granules and a pair of tubercles posteriorly and with posterior margin straight. Mesonotum rugose, indistinctly widening towards the posterior; anterior margin thickened and distinctly concave; lateral margins posterolaterally with some small granules. Mesopleura slightly widened above coxae; widened portion notched medially and slightly crenulated. Metanotum as mesonotum. Metapleura as mesopleura but posterolaterally notched. Prosternum with sensory areas elongate oval, reaching lateral margins. Sensory area on profurcasternum small and circular. Mesosternum with few enlarged black granules.

Legs: femora with carinae indistinct; posteromedially ending with a short dorsal blunt spine. Profemora slightly shorter than mesonotum and curved basally. Mesofemora about as long as metanotum and median segment combined, dorsally with some minute humps; posteroventrally with two pair of granules. Metafemora about as long as profemora; ventrally armed as mesofemora, dorsally with a small hump anteriorly, a lamellate tooth centrally and a rounded tooth subapically. Tibiae with carinae indistinct, slightly shorter than corresponding femora. Protibiae with three minute humps on posterodorsal carina. Mesotibiae with some minute humps dorsally, metatibiae with a minute hump subanteriorly and a larger one centrally. 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 straight. Abdominal terga rugose; terga II–III as median segment but anteriorly with two pairs of sublateral black granules; terga II–IV distinctly widening towards the posterior; III–IV with posterolateral tubercle and IV with indistinct granulose mediolongitudinal carina and posteriorly with twin-crescent-shaped crest; V distinctly narrowing towards the posterior and slightly descending, with X-shaped carina, and posterior armature raised and projecting over posterior margin; tergum VI distinctly descending obliquely and strongly narrowing towards the posterior, medially with a thickened longitudinal carina; tergum VII slightly narrowing towards the posterior, slightly ascending and with indistinct carina mediolongitudinally; tergum VIII about as wide as VII, with posterolateral angles with distinct tubercle and posteromedially with a pair of granules; IX slightly narrower than VIII with central granule and a distinct posteromedial crest; crest relatively short, not notched apically. Anal segment narrower and shorter than tergum IX, obliquely descending and dorsally flattened; anteriorly with a tubercle medially; oblique carinae present as a row of conical tubercles, only lamellate posterolaterally; posterior margin straight, slightly crenulated. Abdominal sterna and subgenital plate with an indistinct mediolongitudinal line. Subgenital plate rugose, boatshaped with widest part at about mid length; posterior rim dorsoventrally flattened and slightly tapering towards the posterior. Apex broadly rounded, almost reaching margin of tergum X.

EGG ( Fig. 8 D–F View Fig.8 ).

Measurements [mm]. Length: 3.5; width: 2.9; height: 3.2.

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 three-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 almost parallel-sided with apex tapering and rounded, almost reaching edge capsule. Posterior arms laterally directed and strongly dilated on lateral surface of capsule, reaching margins of ventral side; almost covering completely lateral side of capsule and almost reaching anterior margin of capsule. Margin of micropylar plate indistinctly raised and demarcated by more dense setae. Micropylar cup small, black, cup-shaped and protruding.

DISTRIBUTION. Vietnam, Ha Long Bay, Cat Ba Island ( Fig. 5 View Fig.5 ).















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