Batriscenellus abdominalis Yin and Wang

Wang, Dan, Yin, Zi-Wei & Li, Li-Zhen, 2015, Two New Species of Batriscenellus Jeannel (Coleoptera: Staphylinidae: Pselaphinae) from China, The Coleopterists Bulletin 69 (3), pp. 405-409 : 405-408

Batriscenellus abdominalis Yin and Wang , new species

( Figs. 1A , 2A, D, H–M )

Type Material. Holotype: ♂, labeled ‘ CHINA: Zhejiang, Lishui City [], Fengyang Shan N. R. [], forest nr. Datianping [], 27°54′33″–55′18″N, 119°10′20″–17″E, mixed litter, moss, sifted, 1170–1300m, 6.x.2013, Feng, Peng, Yu, Yin leg.’ ( SNUC) . Paratypes: 2 ♀♀, same label data as holotype ( SNUC) .

Diagnosis. Male: dorsal surface of the head and pronotum coarsely punctate; legs simple, lacking modification; abdominal tergite IV with a small cavity at posterior half of the tergite, with a small projection posterior to the cavity; aedeagus with a short, broad ventral lobe. Female: tergite VIII rounded and protuberant at middle; genital complex as in Fig. 2K .

Description. Male ( Fig. 1A ). Body reddish brown, length 2.00 mm. Head rectangular, almost as long as wide, HL = 0.43 mm, HW = 0.42 mm, dorsal surface coarsely punctate ( Fig. 2A ); antennal tubercles prominent; vertexal foveae nude, located posterior to point level with anterior margin of eyes; antenna 11-segmented, club formed by apical 3 enlarged antennomeres; ocular-mandibular carinae present; each eye composed of about 30 facets. Pronotum about as long as wide, PL = 0.44 mm, PW = 0.43 mm, coarsely punctate ( Fig. 2A ). Elytra wider than long, EL = 0.59 mm, EW = 0.69 mm, narrowed at base, shallow discal striae extending pass elytral midlength. Legs slender, simple, without modification. Abdomen wider than long, AL = 0.54 mm, AW = 0.63 mm; tergite IV (first visible tergite; Fig. 2D ) longer than V–VII combined, with small cavity at posterior half of tergite, setiferous patches possibly present [indicated by a few remained short setae at both sides of cavity], 1 small projection posterior to cavity; discal carinae distinct, oblique, width between carinae 0.22 mm at base and 0.26 mm at apex. Length of aedeagus 0.26 mm, strongly asymmetric, ventral lobe curved rightwards at middle in ventral view, apex rounded in axial view; dorsal lobe relatively short and broad, broadest near middle, apical portion strongly curved ventrally, flattened ventral membrane present ( Fig. 2H–J ).

Female. Similar to male in general appearance; each eye composed of about 30 facets; tergite IV lacking modification; VIII rounded and protuberant at middle ( Fig. 2L–M ). Measurements: BL = 2.03–2.14 mm, HL = 0.43–0.45 mm, HW = 0.44– 0.44 mm, PL = 0.43–0.44 mm, PW = 0.43– 0.45 mm, EL = 0.58–0.60 mm, EW = 0.69–0.72 mm, AL = 0.59–0.65 mm, AW = 0.67–0.71 mm. Female genital complex well-sclerotized ( Fig. 2K ), width 0.26 mm.

Comparative Notes. Batriscenellus abdominalis is placed as a member of the B. auritus speciesgroup based on the modified abdominal tergite IV of males. Among members of this group, B. abdominalis shares with B. satoi and B. subalpicola a similar aedeagal form. It can be clearly separated from both species by the coarsely punctate dorsal surface of the head and pronotum (versus finely punctate head dorsum and pronotum), as well as the presence of a much smaller cavity on abdominal tergite IV, and the different form of the female genital complex. This new species can be readily separated from the three other species of the group, B. auritus , B. chinensis , and B. pulcher , by the different form of the abdominal modifications.

Distribution. Eastern China: Zhejiang.

Etymology. The species epithet refers to the modifications of abdominal tergite IV.

Figures

Fig. 1. Batriscenellus species, habitus. A) B. abdominalis, B) B. hongkongensis. Scale bars = 0.5 mm.

Fig. 2. Diagnostic characters of Batriscenellus species. A) B. abdominalis, head and pronotum, B) B. hongkongensis, head and pronotum, C) B. hongkongensis, metafemur, D) B. abdominalis, abdominal tergite IV, E–G) B. hongkongensis, aedeagus, lateral, ventral, and axial views, respectively, H–J) B. abdominalis, aedeagus, lateral, ventral, and axial views, respectively, K) B. abdominalis, female genital complex, dorsal view, L–M) B. abdominalis, female tergite VIII, dorsal and axial views, respectively. Scales bars: A, B = 0.3 mm; C, D = 0.2 mm; E–M = 0.1 mm.