Glischrochilus (Librodor) tibetanus Lasoń, 2016

Lasoń, Andrzej & Mazur, Miłosz A., 2016, A new species of the genus Glischrochilus Reitter (Coleoptera: Nitidulidae: Cryptarchinae) from China, Zootaxa 4121 (1) : -

Glischrochilus (Librodor) tibetanus Lasoń , sp. n.

( Figs 1–9 , 15 )

Description. Length 8.50–12.20 (holotype 12.20), maximum width 3.30–4.60 (holotype 4.60). Oblong oval, rather convex, moderately shining. Head, antennae, pronotum, legs with tarsi, elytral epipleura, sutural part of elytra and pygidium reddish brown; each elytron with three yellow-orange spots. The remaining part of elytra, clypeus, inner edge and apex of the mandible and anterior edge of head dark brown. Body in ventral view generally brown (except distinctly darker trochanters).

Head ( Figs 1, 2, 8, 9 ). Broadest between genae (3.60); across eyes almost as wide as distance between anterior pronotal angles. Eyes moderately convex (ca 2.5× as long as wide) and densely faceted. Frons weakly convex, sometimes slightly depressed medially. Vertex convex in lateral view. Apical margin of clypeus narrowed, deeply incised. Punctures of head deep, rather dense, distinctly larger than eye facets; interspaces equal to diameter of punctures or less; on the antennal calli punctures smaller and denser. Antennae almost as long as width of head between antennal insertions; club ca 1.35× longer than wide.

Pronotum ( Fig. 1 ). Widest at three-fifths of length from apical margin; anteriorly distinctly narrowed; 1.64× wider than long; P/A index 1.10. Anterior margin feebly arcuate, not bordered; anterior angles acute, prominent. Base of pronotum almost as wide as elytra, bordered, with broad and rather shallow arcuate emargination next to each posterior angle, which are obtuse and slightly projecting posteriorly. Pronotum laterally broadly rounded; posteriorly almost rectilinear, narrowly canaliculate. Transversely convex; punctures at middle more fine and densely spaced than on frons; interspaces 1.0–2.0× larger than diameters of punctures; in lateral view punctures gradually larger and closely spaced, separated by less than half puncture diameter; interspaces smooth. Apex of scutellar shield rounded; posteriorly with sparse punctures; interspaces slightly wrinkled.

Elytra ( Fig. 1 ). Widest at ca one third of length; elytra together 1.20× longer than maximum width. Humeral angles subrectangular, slightly rounded, dentate. Sutural angle subrectangular, sutural lines distinct in posterior half. Lateral margins narrowly explanate (almost as wide as antennal flagellum) with short cilia. Surface broadly convex; covered with inconspicuous setae; punctures similar as those on pronotum, interspaces 1.0–2.0× larger than diameters of punctures; laterally punctures distinctly densely spaced, interspaces 0.5–1.0× puncture diameter. Each elytron with three yellow-orange spots.

Ventral side ( Figs 3, 4 ). Mentum and genae with very large punctures separated by one diameter or less. Prosternum convex, transversely wrinkled, otherwise with very sparse, shallow punctures. Prosternal process flat, its lateral margins shallowly emarginate; dilated behind procoxae; broadly rounded apically. Punctures on prosternal process single, shallow. Mesoventrite at middle convex and dull, lateral margins deeply grooved. Posterior margin of mesoventrite between mesocoxae with broad, rounded edge. Metaventrite flattened medially with elongate depression behind its midlength; anterior intercoxal process moderately bulged, glabrous. Punctures at middle of metaventrite fine, nearly as large as eye facets, interspaces 1.0–3.0× larger than diameters of punctures; at sides somewhat larger and denser, separated by ca one diameter and bearing recumbent hairs. Punctures of abdominal ventrites similar as on metaventrite, laterally with recumbent hairs. Meso- and metaventral lines closely bordering entire posterior margin of coxal cavities. Hypopygium flattened, with slightly denser punctures, its apical margin bisinuate. Pygidium slightly narrowed apically with rounded apex; densely punctate, obsoletely alutaceous.

Pro-, meso- and metatibia subtriangular, their outer apical angle acute. Outer edge of pro- and mesotibia weakly dentate; metatibia with small granules.

Male terminalia ( Figs 4–6 ). Pygidium subquadrate, almost as long as maximum width at base; apical margin widely rounded with distinct elongate setae. Tegmen short, stout; widest at apical half; ca 1.20× as long as wide; apical margin slightly incised medially. Median lobe of aedeagus in lateral view distinctly convex at base; from dorsal view narrowed before midlength, with pair of longitudinal sclerites situated in centre of lobe.

Female. Very similar to male. Shape of body from dorsal view more regularly oval. Pronotum 1.63–1.67× wider than long, P/A index 1.30–1.33. Elytra 1.18–1.24× as long as their combined width. Ovipositor as in Fig. 7 . Mandibulae as in Fig. 9 .

Differential diagnosis. The new species is similar to G. parvipustulatus (Kolbe, 1886) ( Fig. 14 ) from the Oriental region, but is easy distinguished by body colouration ( G. parvipustulatus is uniformly darker; head, pronotum and elytra of the same colour) and body size ( G. parvipustulatus is much smaller, ca 6.50 mm). Other characters include: dorsum generally glabrous (distinctly scabrous in G. parvipustulatus ), pronotum broadly rounded laterally, medially straight ( G. parvipustulatus with lateral margin medially slightly constricted); body covered with inconspicuous setae (body of G. parvipustulatus covered with conspicuous setae); eyes moderately convex (in G. parvipustulatus eyes are distinctly convex, ca 1.60× as long as wide). Additionally, G. parvipustulatus has different proportion of antennal segments, different shape of tegmen, pygidium and mandibulae than the new species described above ( Figs 10–13 ).

Type locality. China, Tibet Autonomous Region (Xīzàng Zìzhìqū), Chayu county, Xiachayuzhen env.

Type material. Holotype. CHINA (Xīzàng Zìzhìqū province): three labels, ♂: Chayu county, Xiachayuzhen env., VIII 2014, Hu Wei lgt. ( ALPC).

Paratypes. 1♂ —the same data as holotype ( NMPC); 1♂ 1♀—the same data as holotype ( USMB); 2♀♀, the same data as holotype ( ALPC); 1♂ — China, Xîzàng Zìzhìq (Tibet), Motuo county, Renqinpeng, VII 2015, leg. Hu Wei ( ALPC).

Etymology. A toponymical adjective, after the Tibet region.

Habitat and biology. Nothing is known about the life history of this species.

Distribution. This species is known only from southern Tibet, China ( Fig. 15 ).

Figures

FIGURES 1 – 9. Glischrochilus (Librodor) tibetanus sp. n.: 1 — head, pronotum and elytra, dorsal view; 2 — antenna; 3 — prosternal process; 4 — pygidium, male; 5 — tegmen, male; 6 — median lobe of aedeagus, dorsal view; 7 — ovipositor; 8 — mandibulae of male; 9 — mandibulae of female.

FIGURES 14 – 15. Dorsal habitus colour photograph: 14 — Glischrochilus (Librodor) parvipustulatus (Kolbe, 1886); 15 — Glischrochilus (Librodor) tibetanus sp. n.

FIGURES 10 – 13. Glischrochilus (Librodor) parvipustulatus (Kolbe, 1886): 10 — antenna; 11 — tegmen, male; 12 — median lobe of aedeagus, dorsal view; 13 — pygidium, male. (scale bar = 0.5 mm).