Batriscenellus hongkongensis 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 : 408-409

Batriscenellus hongkongensis Yin and Wang , new species

( Figs. 1B , 2B–C, E–G )

Type Material. Holotype: ♂, labeled ‘ China: Hong Kong, Lanran [], Wang Tong [], to light, 27.iv.2010, Paul Aston leg.’ (pcPA) . Paratypes: 5 ♂ ♂, from the same locality by light trap as the holotype, except collecting date from 18.vi.2010 to 21.xi.2012 (pcPA, SNUC) .

Diagnosis. Male: dorsal surface of the head and pronotum finely punctate; metafemur enlarged at apical half; abdominal tergites simple, lacking modification; aedeagus with an elongate, twisted ventral lobe.

Description. Male ( Fig. 1B ). Body reddish brown, length 1.97–2.08 mm. Head rectangular, slightly wider than long, HL = 0.38–0.40 mm, HW = 0.42–0.43 mm, dorsal surface finely punctate ( Fig. 2B ); antennal tubercles moderately prominent; vertexal foveae nude, located posterior to level of anterior margin of eyes; antenna 11-segmented, club formed by apical 3 enlarged antennomeres; ocularmandibular carinae present; each eye composed of about 25 facets. Pronotum slightly longer than wide, PL = 0.45–0.47 mm, PW = 0.43 mm, finely punctate ( Fig. 2B ). Elytra wider than long, EL = 0.59–0.66 mm, EW = 0.69–0.72 mm, narrowed at base, shallow discal striae extending to apical 3/4 of elytral length. Metafemur enlarged at apical half ( Fig. 2C ), surface with short, dense sensory setae. Abdomen wider than long, AL = 0.53–0.57 mm, AW = 0.69–0.72 mm; all tergites simple without modification; discal carinae of tergite IV (first visible tergite) short, almost parallel, width between carinae 0.28 mm. Length of aedeagus 0.34 mm, strongly asymmetric, ventral lobe curved rightwards at apex in ventral view, apex tapered in axial view; dorsal lobe elongate, strongly twisted before middle, apical portion strongly curved ventrally, flattened ventral membrane present ( Fig. 2E–G ).

Female. Unknown.

Comparative Notes. Batriscenellus hongkongensis is placed in the B. uenoi species-group based on the simple abdominal tergite IV and modified metafemur of the male. It is similar to B. uenoi Nomura , sharing enlarged metafemora that are densely covered with sensory setae on the dorsal surfaces. The two species can be readily separated by the relatively much longer and more slender aedeagal dorsal lobe in B. hongkongensis . Batriscenellus hongkongensis can be separated from B. femoralis by the less densely punctate clypeus and head dorsum and apical halves of the metafemora somewhat flatly broadened in the male, while males of B. femoralis possess cylindrically broadened apical halves of the metafemora.

Distribution. Southern China: Hong Kong

Etymology. The specific epithet is taken from its type locality.

MODIFIED COUPLETS OF THE KEY TO CHINESE BATRISCENELLUS (YIN ET AL. 2011)

Note. One of the Chinese species, B. orientalis , was missing from the original key and is added below.

1 Abdomen simple in structure, without sensory setae, patch or excavation ................. 1a

– Abdominal tergites IV–VI with either specialized setae, or patch, or excavation.............2

1a Metaventrite with a pair of setiferous patches between the metacoxae; metafemora not modified. ( North Korea; South Korea; China: Zhejiang, Shanghai, Taiwan) ( B. similis species-group)..................... B. orientalis (Löbl)

– Metaventrite lacking setiferous patches between the metacoxae; metafemora modified ( B. uenoi species-group).....................1b

1b Head dorsum and clypeus coarsely punctate; metafemur cylindrically enlarged in apical half; dorsal lobe of aedeagus relatively shorter, apex curved upwards in ventral view. ( China: Zhejiang) ................. B. femoralis Yin and Li

– Head dorsum and clypeus finely punctate; me-

tafemur enlarged and flattened in apical half;

dorsal lobe of aedeagus relatively longer, apex

curved downwards in ventral view. ( China:

Hong Kong) ....... B. hongkongensis Yin and

Wang, new species

6 Head dorsum and pronotum coarsely punctate. ( China: Zhejiang) .......... B. abdominalis Yin and Wang , new species

– Head dorsum and pronotum finely punctate ................................................................. 6a

6a Length more than 2.00 mm; tergite IV with base of excavation bearing filament structure; aedeagus in lateral view with short ventral lobe, dorsal apophysis not split in apical half. ( China: Sichuan) ............ B. satoi (Nomura)

– Length less than 1.75 mm; tergite IV lacking filament structure; aedeagus in lateral view with distinctive elongate ventral lobe, dorsal

apophysis bifurcate in apical half. ( North Korea; China: Zhejiang) ................. B. auritus (Löbl)

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.