Belonuchus imitator Cameron, 1932

Li, Liang & Zhou, Hong-Zhang, 2010, Revision of the Chinese species of the genus Belonuchus Nordmann (Coleoptera: Staphylinidae: Philonthina), Journal of Natural History 44 (35 - 36), pp. 2149-2177 : 2165-2167

Belonuchus imitator Cameron, 1932 , first record from China

( Figure 7A–I )

Cameron 1932: 176: ( Belonuchus , Type locality: Burma: Schwego-myo); Scheerpeltz 1933: 1378 ( Belonuchus , catalogue); Herman 2001: 2527 ( Belonuchus , world catalogue).

Examined material

Syntype: one male, Birmania, Shwego-myo , Fea. Ottobre, 1885 ( NHML) ; three males, two females, China: Hainan: Danzhou : 11 April 2008, Li Liang collected (IZ- CAS) ; one female, China: Hainan: Xinglong: Zhiwuyuan , 41 m, 22 March 2008, Li Liang collected (IZ-CAS) ; one male, China: Fujian: Nanjing: Huboliao: Xiangxi , 195 m, 23 November 2008, Wang Fengyan collected (IZ-CAS) ; four males, Hainan: Lingao , 24 June 1957 (IZ-CAS) ; one female, Vietnam: Tonkin: Hoa-Binh , July 1937, A. de Cooman collected (IZ-CAS) .

Description

Head and pronotum black, shining. Elytra black or black-brown. Scutellum black. Antennae black or black-brown with antennomere XI sometimes reddish-brown. Abdomen black with feebly blue lustre. Mandibles dark brown. Maxillary and labial palpi reddish-brown. Legs black-brown.

Body depressed, 10.0– 11.8 mm long (HPL: 3.10–3.84 mm). Head obtusely quadrangular, 1.55–1.96 mm long, 1.71–2.04 mm wide, slightly wider than long (HW: HL = 1.04–1.11), distinctly widened posteriad behind eyes, with broadly obtuse hind angles. Frons with slightly longitudinal median impression and six punctures placed in a square. Tempora 0.73–0.98 mm long, sparsely and coarsely punctate, with a carina extending ventrally from posterior margin of tempora; eyes small, slightly prominent, 0.41–0.49 mm long, 0.50–0.67 times as long as tempora. Lateral portions of head with scattered, large, setiferous punctures; vertex largely impunctate; entire head with distinct and profound microsculpture of long waves. Antennae very short, antennomere I very long, thickened towards apex, antennomere III distinctly longer than antennomere II, antennomeres IV–X distinctly transverse, antennomere XI almost as long as wide, obliquely truncate.

Pronotum distinctly narrowed posteriad, lateral margin slightly concave in posterior half; 1.47–1.71 mm long, 1.47–1.80 mm wide, slightly narrower than head (PW: HW = 0.79–0.88); front angles very characteristic, almost acute; dorsal rows each with five to seven large punctures, lateral portions each with five or six large punctures; microsculpture fine, similar to that on head.

Elytra slightly widened posteriad, 1.80–2.12 mm long, 1.80–2.28 mm wide, along sides 1.15–1.33 times as long as pronotum, densely and finely punctate, punctures separated by one or two times their diameter. Scutellum large, triangular, densely and finely punctate.

Abdomen slightly narrowed posteriad, widest 1.71–2.04 mm, finely and closely punctate, punctures separated by two to three times their diameter at base, gradually and distinctly becoming sparser toward apex of each tergite; surface between punctures with exceedingly fine and dense microsculpture of transverse striae; first three visible abdominal tergites with two basal lines, elevated area between basal lines with one or two more or less irregular rows of fine punctures.

Male. Anterior tarsomeres I–IV dilated, with modified pale setae ventrally. Sternite VIII with inconspicuous, medio-apical emargination ( Figure 7G ). Genital segments with styli of tergite IX simple, moderately setose apically. Sternite IX with markedly asymmetrical proximal portion, moderately deep emarginate apically; each lobe with one long apical seta ( Figure 7F ). Tergite X simple, triangular, subtruncate at apex, with numerous apical setae ( Figure 7I ).

Aedeagus short, with median lobe distinctly exceeding paramere, apical portion slightly narrowed ( Figure 7A ); in lateral view, median lobe distinctly widened anteriad, with a very small tooth subapically ( Figure 7B ); paramere distinctly narrower than median lobe, subrounded at apex, face adjacent to median lobe with sensory peg setae arranged along lateral-apical margins of paramere ( Figure 7C–E ).

Female. Anterior tarsomeres I–IV slightly dilated, with modified pale setae ventrally. Sternite VIII subrounded at apex, without medio-apical emargination. Genital segments with styli of tergite IX similar to that of male. Tergite X triangular, subrounded at apex, with numerous setae ( Figure 7H ).

Distribution

China (Hainan, Fujian), Vietnam, Myanmar.

Remarks

Cameron (1932) described this species from Myanmar. Our specimens agree well with Cameron’s syntype (NHML). Belonuchus imitator Cameron, 1932 is similar to B. mutator Fauvel, 1879 in having tempora with a carina and very characteristic front angles of pronotum. Belonuchus imitator differs from B. mutator by different morphology of paramere (paramere with very acute apex and fewer of peg setae in B. mutator ).

Figures

Figure 7. Belonuchus imitator Cameron, 1932. (A) Aedeagus, ventral view; (B) median lobe of aedeagus, lateral view; (C–E) underside of paramere; (F) sternite IX of male; (G) sternite VIII of male; (H) tergite X of female; (I) tergite X of male. Scale bars 0.5 mm.