Bellenden siguniang Yin & Jiang

Yin, Zi-Wei & Jiang, Ri-Xin, 2016, Taxonomic notes on the genus Bellenden Chandler (Coleoptera, Staphylinidae, Pselaphinae), ZooKeys 638, pp. 27-32 : 29-31

Bellenden siguniang Yin & Jiang sp. n. Fig. 1 A–C

Type material

(1 ♂, 5 ♀♀). Holotype: CHINA: ♂, labeled 'China: Sichuan, Xiaojin County (小金县), Siguniang Shan (四姑娘山), Haizigou (海子沟), 30°59'57"N, 102°50'51"E, leaf litter, sifted, 3,340 m, 17.vii.2015, J(iang), P(eng), T(u), Z(hou) leg.' (SNUC). Paratypes: CHINA: 5 ♀♀, same collecting data as the holotype (SNUC).

Diagnosis.

Lateral margins of frontal rostrum before eyes sloping anteriorly, roundly dilating laterally at level of antennal bases; maxillary palpomere I only slightly shorter than II; male lacking ventral protuberance at ventral margin of the protrochanter, metaventrite unmodified; impressed area of sternite IV longer than wide and almost reaching posterior margin of the segment.

Description.

Male (Fig. 1A), length 2.35 mm (combined length of head, pronotum, elytra and abdomen), body uniformly reddish-brown, pubescence recumbent and sparse. Head longer than wide, length from anterior clypeal margin to occipital constriction 0.47 mm, width across eyes 0.27 mm (Fig. 1B), frontal rostrum conspicuously narrowing anteriorly in front of anterior margin of eyes and dilating at level of antennal bases (Fig. 1B); anterior margin of frons with small triangular projection at middle, frontal sulcus without dense apical pubescence, narrow and deep anteriorly and somewhat dilating and gradually disappearing posteriorly; each eye with nine small facets; maxillary palpus (Fig. 1C) elongate, palpomere II longer than palpomere I; length of palpomere 1.05 mm, palpomere I 0.2 mm, II 0.27 mm, III 0.07 mm, IV 0.51 mm. Length of antenna 1.3 mm; antennomere I subcylindrical, more than three times as long as wide, slightly wider than antennomere II; antennomere II about 1.5 times as long as wide; antennomeres III–VIII of subequal width, slightly narrower than antennomere II, antennomeres III–VII approximately twice as long as wide, antennomere VIII slightly shorter, and antennomere IX considerably wider than preceding segments, approximately as wide as antennomere II, but much longer, approximately twice as long as wide; antennomere X somewhat slightly wider than antennomere IX, antennomere XI shorter than antennomeres IX and X together, but considerably wider than them, widest slightly before middle. Pronotum widest near middle, length along midline 0.48 mm, maximum width 0.38 mm; antebasal fovea small, puncture-like, lateral foveae larger. Elytra wider than long, length along suture 0.58 mm, maximum width 0.78 mm, covered with relatively dense long hairs along posterior margin; sutural and discal striae narrowed at base; sutural stria conspicuously deeper at base than discal stria; discal stria extending posteriorly to 3/4 elytral length. First tergite largest, widest near middle. Length of dorsally visible part of abdomen (posterior to elytra) along midline 0.82 mm, maximum width 0.92 mm; sternite IV (second visible sternite) slightly impressed medially. Aedeagus (Fig. 1C) slightly asymmetric dorso-ventrally, length 0.48 mm.

Female, similar to male in general appearance; each eye composed of nine small facets. Measurements of body parts: body length 2.24 mm, length of head 0.44-0.46 mm, width of head 0.27-0.29 mm, length of antenna 1.19-1.20 mm, length of pronotum 0.43-0.44 mm, width of pronotum 0.38 mm, length of elytra 0.59-0.61 mm, width of elytra 0.77-0.80 mm, length of abdomen 0.75-0.76 mm, width of abdomen 0.87 mm.

Comparative notes.

Bellenden siguniang is similar to Bellenden botellarius and Bellenden jingyuanensis by sharing unmodified male protrochanter and metaventrite. The new species can be separated from Bellenden botellarius by the lateral margins of the frontal rostrum before eyes gradually sloping anteriorly and then roundly dilating at antennal bases, and from Bellenden jingyuanensis by the much large body size. The lateral margins of the frontal rostrum in Bellenden botellarius are parallel-sided and barely dilated at antennal bases, and the body length of Bellenden jingyuanensis measures only 1.89 mm. Bellenden jingyuanensis similarly has the lateral margins of the frontal rostrum narrowing anteriorly, when combined with the structures of the aedeagal endophallus, it can be readily distinguished from Bellenden botellarius . The other three species, Bellenden monteithi , Bellenden belousovi and Bellenden nubigena , all have spinose/protuberant protrochanter in the male, thus are easily separable from Bellenden siguniang . Moreover, the aedeagal endophallus of Bellenden siguniang has a pointed and curved apex, which alone can be used to discriminate the new species from all other congeners.

Distribution.

Southwestern China: Sichuan.

Etymology.

The specific epithet is taken from the type locality of the new species, i.e., Siguniang Mountain.