Microrestes, Bresseel & Constant, 1877

Bresseel, Joachim & Constant, Jérôme, 2020, Microrestes gen. nov., a new genus in the Oriental stick insect tribe Datamini Rehn & Rehn, 1939 with a new species and a new combination (Phasmida: Heteropterygidae: Dataminae), Belgian Journal of Entomology 106, pp. 1-19 : 1-19

Genus Microrestes gen. nov.

urn:lsid:zoobank.org:act:8BE4525B-D4C8-4EC5-92CD-324D0BF86F43

TYPE SPECIES: Microrestes robustus sp. nov. by present designation.

ETYMOLOGY. The genus name is formed by the combination of “ Micr -” derived from the greek word μικρός (micros) meaning small and “- orestes ”, the name of another genus in Dataminae . It refers to the small size of the new genus and its close relationship with Orestes Redtenbacher, 1906 . Gender masculine.

DIAGNOSIS. Differing from all other known genera of Dataminae by the following combination of characters:

1) Body length of females <40mm, males <35mm.

2) Scapus with two spines and pedicellus with one spine on the outer lateral margin.

3) Pronotum trapezoidal with anterior margin narrower than posterior margin.

4) Prosternum with three sensory areas and profurcasternum with one sensory area ( Fig 2 .). 5) Mesonotum trapezoidal with anterior margin wider than posterior margin.

6) Meso- and metanotum with lateral margins thickened and with a distinct mediolongitudinal carina.

7) Poculum in males more or less bowl-shaped, apical portion flattened and notched.

8) Anal segment in females more or less rectangular in dorsal view, not distinctly tapering towards the posterior.

9) Egg capsule smooth and minutely pitted, micropylar plate with anterolateral arms reaching ventral surface.

DIFFERENTIAL DIAGNOSIS. The new genus shows close relationship with Orestes Redtenbacher, 1906 and Pylaemenes Stål, 1875 . With Pylaemenes it shares the trapezoidal pronotum but differs by the posteriorly straight anal segment and by the not laterally expanding abdominal terga VIII–IX. With Orestes it shares the almost parallel-sided anal segment which is dorsally flattened in females and has two distinct tuberculose oblique carinae, but can be differentiated by the trapezoidal meso- and metanotum. Eggs can readily be differentiated from those of Orestes and Pylaemenes by completely lacking setae on capsule.

DESCRIPTION

MALE AND FEMALE

Body: Males mainly brown to almost black, females colouration more variable, but predominantly brown, sometimes with some light brown mottling.

Head: Supra-antennals and supra-occipitals present, supra-occipitals not split into anterior and posterior supra-occipitals. Vertex raised and slightly projecting over anterior margin of pronotum. Supra-orbitals, pro-coronals and anterior coronals present, spinose in males, lamellate and carinate in females. Posterior coronals and lateral coronals present. Postocular carina distinct with a definite blunt spine apically. Eyes relatively small, almost circular and projecting laterally. Antennae shorter than front legs; scapus strongly flattened dorsally, carinate laterally and with a central and a subapical blunt spine on outer lateral carina; pedicellus with a blunt spine on outer lateral margin. Third antennomere longer than following two antennomeres combined.

Thorax: Pronotum transverse, trapezoidal and widening towards the posterior; anterior margin concave. Posterior margin distinctly wider than anterior margin and straight. Mesonotum trapezoidal with anterior margin wider than posterior margin and with an anterolateral granule or spine; anterior margin raised medially, lateral margins thickened; mediolongitudinal carina

distinct; in lateral aspect, anterolateral margin distinctly lower than posterolateral margin. Prosternum with three sensory areas, lateral areas elongate oval, central area small and circular. Sensory area on profurcasternum small and circular.

Abdomen: Median segment rugose, strongly transverse and with posterior margin more or less straight; medially with raised longitudinal carina, diverging near posterior margin. Abdominal terga rugose and transverse; terga II–IV gradually widening towards the posterior, tergum IV and V more or less parallel-sided. Females with anal segment dorsally flattened, sublaterally with oblique row of minute tubercles that reaches up to the posterolateral angles; posterior margin straight. Subgenital plate with posterior portion strongly rounded in lateral view; ventral portion with three longitudinal carinae, one medially and two submedially; not reaching apex of tergum X. Males with anal segment somewhat flattened, incised posteromedially and posterolaterally; posterolateral angles indistinctly raised. Poculum with anterior portion rounded and medially keeled; posterior portion distinctly flattened and notched apically. Cerci very small, dorsoventrally flattened, not reaching apex of abdomen.

EGG. Capsule blackish and spherical, capsule surface minutely pitted. Micropylar plate distinct, dorsal portion narrow and nearly reaching to operculum; posteriorly diverging with posterolateral arms surrounding capsule and reaching ventral surface of capsule with apices rounded or merging. Micropylar cup small, with a short median line that reaches the polar area. Operculum slightly convex, almost circular.

DISTRIBUTION. Currently known from North Vietnam, southwest China and northern Thailand ( Fig. 3 ).

SPECIES INCLUDED:

M. robustus sp. nov.

M. trapezius (Ho, 2016) comb. nov.

[ Vietnam: Ngoc Son-Ngo Luong N.R.]

[ China: Xishuangbanna]

Figures

Fig. 2. Microrestes robustus sp. nov., prosternal sensory organs. A, paratype ♂. B, holotype ♀.

Fig. 3. Microrestes spp. distribution map.