Labomimus dilatatus, Zhang & Li & Yin, 2019

Zhang, Yu-Qing, Li, Li-Zhen & Yin, Zi-Wei, 2019, Fifteen new species and a new country record of Labomimus Sharp from China, with a checklist of world species (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 4554 (2), pp. 497-531 : 503-506

Labomimus dilatatus sp. nov.

( Figs. 4B , 6 )

Type material ( 1 ♂). Holotype: CHINA: ♂: ‘ CHINA: Shaanxi, Nanzheng County (南郑县), Liping National Forest Park (里坪森林公园), 32°49′55′′N, 106°36′33′′E, 14 00– 1600 m, mixed leaf litter, sifted, 16.vii.2012, L.- Z. Li leg.’ ( SNUC).

Diagnosis of male. Length slightly over 3.50 mm; postgenae broadly expanded laterally; antennomeres VIII– X strongly modified, VIII angulate at apicolateral corner, IX strongly elongate and expanded laterally, X

transverse, broadly concave at base in lateral half; pronotum with round lateral margins; elytra in contrast to abdomen relatively small; metaventral processes long; protibia with acute projection; metacoxa with hook-like ventral projection; aedeagus slightly asymmetric, with median lobe strongly narrowed at apex.

Description. Male ( Fig. 4B ). Length 3.55 mm. Head longer than wide, HL 0.79 mm, HW 0.69 mm; postgenae expanded laterally, frons between antennal insertions broad; eyes small, each composed of about 25 facets. Antenna with scape about 4.3 times as long as wide, antennomeres II–VII similar, each slightly elongate, antennomere VIII angularly expanded laterally at apex, antennomere IX ( Fig. 6A ) much longer than wide, strongly expanded laterally, antennomere X strongly transverse, broadly concave at base in lateral half. Pronotum ( Fig. 6B ) slightly longer than wide, PL 0.73 mm, PW 0.69 mm, with round lateral margins. Elytra small, much broader than long, EL 0.81 mm, EW 1.0 mm. Metathoracic wings reduced. Metaventral processes ( Fig. 6C ) long, blunt apically in lateral view. Protrochanter and profemur ( Fig. 6D ) simple, protibia ( Fig. 6E ) with distinct and apically narrowing projection; mesotrochanter and mesofemur ( Fig. 6F ) simple; metacoxa ( Fig. 6G ) with long, hook-like projection at ventral margin. Abdomen broad at base and narrowed posteriorly, AL 1.22 mm, AW 1.23 mm; tergite IV longest, more than twice as long as tergite V; sternite IX as in Fig. 6H . Length of aedeagus ( Fig. 6 I–K) 0.50 mm; median lobe nearly symmetric, narrowing at apex; elongate parameres broadened dorsoventrally through entire length, blunt at apices.

Female. Unknown.

Distribution. China: Yunnan.

Etymology. The specific epithet refers to the dilate postgenae of the male of the new species.

Comparative notes. The new species is placed as a member of the L. shibatai -group based on the laterally expanded postgenae and rounded pronotal lateral margins. Labomimus dilatatus sp. nov. is closest to L. longnan sp. nov. (described below) by sharing a similar form of the antennomeres IX–X, and the relatively small elytra. The reduced hind wings in both species indicate a poor ability of dispersal that they may confined to a small geographical area. These two species can be readily separated by the more strongly modified antennomere VIII, by the differently formed antennomere IX, and by the border subapical portion of the median lobe of the aedeagus of L. dilatatus sp. nov..

Figures

FIGURE 4. Dorsal habitus of Labomimus males. A. L. corpulentus. B. L. dilatatus. Scale bar: 1 mm.

FIGURE 6. Diagnostic features of Labomimus dilatatus, male. A. Antennal club. B. Pronotum. C. Metaventral process, in lateral view. D. Protrochanter and profemur. E. Apex of protibia. F. Mesotrochanter and mesofemur. G. Metatrochanter and metafemur. H. Sternite IX. I–K. Aedeagus, in dorsal (I), lateral (J), and ventral (K) view. Scale bar: A, B, D, F, G = 0.3 mm; C, I, J, K = 0.2 mm; H = 0.1 mm; E = 0.05 mm.