Tetranillus nyingchiensis, Ba & Ren, 2013

Ba, Yi-Bin & Ren, Guo-Dong, 2013, Two new species and one new combination of Stenosini (Coleoptera: Tenebrionidae) from Xizang, China, Acta Entomologica Musei Nationalis Pragae 53 (2), pp. 697-702 : 698-699

Tetranillus nyingchiensis sp. nov.

( Figs 1–6 )

Type locality. China, Xizang province, Nyingchi county, Bayi town (alt. 3350 m).

Type material. HOLOTYPE: J, ‘ CHINA: XIZANG: Nyingchi County, Bayi Town (Alt. 3350m), 12.vii.2008, Ren Guodong leg.’ ( MHBU) . PARATYPES: 12 JJ 16 ♀♀, same label data as holotype ; 11 JJ 12 ♀♀, ‘ CHINA: XIZANG, from Nyingchi County to Gongbo’gyamda County (alt. 2800–4000 m), 21.viii.2003, Ren Guodong leg.’ ( MHBU) .

Description. Body brown, elytra paler.

Head oval, 1.4 times as long as wide, widest in front of eyes. Dorsum uniformly covered with dense oval punctures, each with one yellow seta, punctures on clypeus smaller; median carina long, almost reaching anterior margin of eyes, lateral carinae straight and covering inner part of eyes a little. Anterior margin of clypeus double concave, left concavity deeper. Genae slightly expanding before eyes, straightly narrowing forwards. Eyes completely divided by genae, dorsal side of eyes with about 16 facets in four rows, ventral side of eyes with about 7 facets in three rows. Tempora almost straight. Antennae strong, reaching basal 1/3 of pronotum; each antennomere 2–9 shortly claviform; relative length ratio of antennomeres 2–11 as follows: 10.9: 14.7: 10.8: 10.0: 9.6: 9.6: 9.2: 9.0: 11.0: 11.0.

Pronotum approximately inversely trapezoid, 1.2 times as long as wide, widest at apical 1/3. Anterior margin undulated, lateral margins somewhat undulated, slightly carinate and serrate, basal 1/4 somewhat parallel; posterior margin straight. Anterior angles acute and protruding, slightly extending outward; posterior angles acute and protruding. Dorsum strongly convex, with wide median depression; rounded punctures dense, each with a short yellow seta; two sharp carinae arched. Propleura densely covered with strong punctures; each with a short yellow seta.

Elytra oblong, 2.0 times as long as wide, and 1.9 times as wide as pronotum, widest at apical 1/3. Humeral angles pointed. Dorsum weakly convex; elytron with 10 rows of strongly rounded punctures and with four sharp carinae from epipleuron to median suture on interval 3, 5, 7, and 9; each puncture with one short yellow seta. Epipleura with a row of strong rounded punctures.

Abdomen covered with strong oval punctures, each with a yellow seta. Legs slender, densely covered with yellow setae; ratio of lengths of metatarsomeres 1–4 as follows: 17.4: 11.5: 12.0: 22.0. Aedeagus 1.3 mm long; apex of paramere pointed, with 3 to 5 fine apical setae.

Measurements. Body length 4.5–6.5 mm; width 1.0–2.0 mm.

Differential diagnosis. The new species is similar to Tetranillus longicarinatus Ren & Shi, 2006 , but differs from the later as follows: median carina of head almost reaching anterior margin of eyes, lateral carinae covering the inner part of eyes a little; antennomeres 2–9 shortly claviform ( Fig. 4 ); antennomere 3 is 1.4 times longer than antennomere 4, T. longicarinatus has antennomere 3 only 1.1 times longer than antennomere 4; and the shape of pronotum is different from T. longicarinatus .

Etymology. Named after Nyingchi County where the type series was collected.

Distribution. China: Xizang.

Figures

Figs 1–6. Tetranillus nyingchiensis sp. nov. 1 – habitus; 2 – head and pronotum, dorsal view; 3 – head, lateral view; 4 – antenna; 5–6 – aedeagus: 5 – ventral view, 6 – dorsal view. Scale bars = 1.0 mm.