Labomimus dilaticeps, Zhang & Yin, 2019

Zhang, Yu-Qing & Yin, Zi-Wei, 2019, Three new species of Labomimus Sharp (Coleoptera: Staphylinidae: Pselaphinae) from Taiwan, China, with an updated key for L. shibatai Sawada-group, Zootaxa 4586 (3), pp. 553-561 : 554-557

Labomimus dilaticeps sp. nov.

( Figs 3A , 4 )

Type material ( 5 exx). Holotype: CHINA: Taiwan: ♂: ‘ Meifeng (2100 m), NANTOU TAIWAN, 南投縣梅峰,

26. X. 2000, Hroshi Sugaya leg. (in the leaf litter)’( MHNG) . Paratypes: CHINA: Taiwan : 3 ♀♀: same data as the holotype ( MHNG, SNUC) ; 1 ♂: ‘ TAIWAN, Pingtung Hsien, Peitawushan ridge (北大武山), 2800–2910 m, 28. IV. 1992, A. Smetana [T105]’ ( SNUC) .

Diagnosis of male. Length over 3.50 mm. Postgenae broadly expanded laterally. Antennomere 9 enlarged, with long pubescence at anterolateral corner, antennomere 10 strongly transverse, antennomere 11 expanded mesally. Pronotum with round lateral margins. Metaventral processes moderately elongate, acute at apex. Protibiae with blunt apical spur; mesotrochanters with small ventral spine; metacoxae with long projection on ventral margin. Aedeagus elongate, median lobe slightly asymmetric at apex.

Description. Male ( Fig. 3A ). Length 3.64–4.05 mm. Head slightly longer than wide, HL 0.78–0.92 mm, HW 0.76–0.89 mm; postgenae expanded laterally; eyes small, each composed of about 22 facets. Antennae with scape (antennomere 1) about 3.8 times as long as wide, antennomeres 2–7 each strongly to slightly elongate, antennomere 8 about as long as wide, antennomeres 9–10 ( Fig. 4A ) enlarged, 9 with long golden pubescence at anterolateral corner, antennomere 10 strongly transverse, antennomere 11 expanded on mesal margin. Pronotum ( Fig. 4B ) slightly longer than wide, PL 0.71–0.83 mm, PW 0.68–0.76 mm, with round lateral margins. Elytra much broader than long, EL 0.84–0.90 mm, EW 1.22–1.24 mm. Metaventral processes ( Fig. 4C ) long, narrowed apically, with short protuberance above metacoxae. Protrochanters and profemora ( Fig. 4D ) simple, protibiae ( Fig. 4E ) with small, blunt apical projection; mesotrochanters ( Fig. 4F ) with small, acute ventral spine, mesofemora strongly expanded; metacoxae ( Fig. 4G ) with long, apically truncate ventral projection. Abdomen broad at base and narrowed posteriorly, AL 1.31–1.41 mm, AW 1.23–1.34 mm; tergite 1 (IV) longest, more than twice as long as tergite 2 (V); sternite 7 (IX) as in Fig. 4H . Length of aedeagus ( Fig. 4 I–K) 0.60 mm; median lobe elongate and slightly asymmetric, narrowing apically; elongate parameres broadened dorso-ventrally; endophallus comprised of two short, and one long sclerite.

Female. Similar to male in general appearance; eyes smaller, each composed of about 26 facets; antennae simple, lacking metaventral processes; mesotrochanters with two distinct spines at ventral margin. Measurements: BL 3.58–3.78 mm, HL 0.78–0.83 mm, HW 0.66–0.69 mm, PL 0.74–0.82 mm, PW 0.71–0.77 mm, EL 0.81–0.84 mm, EW 1.25–1.32 mm, AL 1.25–1.29 mm, AW 1.38–1.41 mm.

Distribution. China: Taiwan.

Etymology. The new specific epithet refers to the dilated postgenal area of the male.

Comparative notes. The new species is placed as a member of the L. shibatai -group based on the laterally expanded postgenae of the male. It is most similar to L. dabashanus Yin & Li from Hubei and Shaanxi, and L. jiudingensis Yin & Nomura from Sichuan in the strongly transverse antennomere 10 of the male. For separation of these three species see the key below.

Figures

FIGURE 3. Dorsal habitus of Labomimus dilaticeps (A), and L. sugayai (B). Scale bar: 1.0 mm.

FIGURE 4. Diagnostic features of Labomimus dilaticeps, 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), 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.