Batrisodes petalosus Jiang and Yin

Jiang, Ri-Xin & Yin, Zi-Wei, 2016, Two new species of Batrisodes Reitter (Coleoptera: Staphylinidae: Pselaphinae) from China, Zootaxa 4205 (2), pp. 194-200 : 197-198

Batrisodes petalosus Jiang and Yin , new species

( Figs 3–4 )

Type material. （2 ♂♂, 1 ♀）. Holotype: CHINA: ♂, labeled ‘ CHINA: Ningxia, Longde County (隆德县), Liupan Shan N. R. (六盘山自然保护区), vi.2008, Bi Wen-Xuan leg.’ ( SNUC) . Paratypes: CHINA: 1 ♂, 1 ♀, same label data as the holotype ( SNUC).

Diagnosis of male. The new species is distinct among its Palaearctic congeners by possessing enlarged and flattened pedicel in the male, which is about four times as long as antennomere III. When combined with the frontal modifications ( Fig. 4 A) and aedeagus (median lobe apically expanded; Fig. 4 F), it can be readily separated from all other European and East Asian species.

Description. Male ( Fig. 3 A). Body reddish brown, BL 2.86–2.90 mm. Head ( Fig. 4 A) wider than long, roundly rectangular, HL 0.61–0.65 mm, HW 0.68–0.69 mm, with distinct, nude vertexal foveae, antennal tubercles prominent; anterior margin of frons strongly sinuate, with five bunches of thick setae anteromedially, area between antennal tubercles concave; clypeus medially impunctate, with round anterior margin; short lateral longitudinal carinae extending from level of vertexal foveae posteriorly to occipital constriction, lacking median vertexal carina. Each eye composed of about 50 facets. Antenna ( Fig. 4 C) moniliform, with 11 antennomeres, club formed by three apical antennomeres; scape broad, slightly elongate, pedicel larger than scape, widest at apex. Pronotum about as long as wide, PL 0.57–0.60 mm, PW 0.61–0.62 mm, rounded laterally, disc slightly convex, with distinct median antebasal foveae, median and lateral longitudinal sulci present; outer and inner basolateral foveae small but distinct. Elytra slightly wider than long, EL 0.88–0.89 mm, EW 0.90–0.93 mm; each elytron with three large basal foveae; discal striae shallow and short. Mesofemur ( Fig. 4 D) with tiny ventral spine near middle; mesotibiae ( Fig. 4 E) with small ventral denticle at basal 3/5, and large triangular apical spine. Abdomen wider than long, AL 0.76– 0.80 mm, AW 0.85–0.87 mm; tergite IV longest, about twice as long as next, with strongly oblique marginal carinae. Length of aedeagus ( Fig. 4 F–G) 0.45 mm; median lobe simple, flattened, apically expanded, nearly symmetric.

Female ( Fig. 3 B). General habitus similar to male, frons ( Fig. 4 B) unmodified; each eye composed of about 35 facets, and with one short ocular spine; pedicel not dilated as in male, only about twice length of antennomere III; legs lacking denticle and spine; tergite VIII ( Fig. 4 H) semicircular; sternite VIII ( Fig. 4 I) transverse; symmetric genital complex ( Fig. 4 J) weakly sclerotized, width 0.27 mm. Measurements of body parts: BL 2.96 mm, HL 0.62 mm, HW 0.72 mm, PL 0.61 mm, PW 0.62 mm, EL 0.87 mm, EW 0.96 mm, AL 0.86 mm, AW 0.92 mm.

Distribution. Northwestern China: Ningxia.

Host ant. Myrmica sp.

Etymology. The specific epithet is derived from the Greek adjective ‘petalos’, meaning ‘flat, spread out’, referring to the flattened and enlarged male pedicel of the new species.

Figures

FIGURE 3. Dorsal habitus of Batrisodes petalosus. A. Male; B. Female. Scale: 0.5 mm.

FIGURE 4. Diagnostic features of Batrisodes petalosus (A, C – G. Male. B, H – J. Female). A, B. Head, in dorsal view. C. Antenna. D. Mesofemur. E. Mesotibia. F. Aedeagus, in ventral view. G. Same, in lateral view. H. Tergite VIII. I. Sternite VIII. J. Genital complex. Scales: A – G = 0.2 mm; H – J = 0.1 mm.