Xanthocorus nigromarginatus (Miyatake, 1970)

Li, Wenjing, Chen, Xiaosheng, Wang, Xingmin & Ren, Shunxiang, 2015, Contribution to the genus Xanthocorus Miyatake (Coleoptera, Coccinellidae, Chilocorini), ZooKeys 511, pp. 89-98 : 91

Taxon classification Animalia Coleoptera Coccinellidae

Xanthocorus nigromarginatus (Miyatake, 1970) Figs 1 a–j, 2 a–i, 5

Exochomus (Xanthocorus) nigromarginatus Miyatake, 1970: 312; Pang and Mao 1979: 76; Cao et al. 1992: 152; Pang et al. 2004: 316; Ren et al. 2009: 136.

Xanthocorus nigromarginatus : Kovář, 1997: 24.

Diagnosis.

This species can be distinguished from other species of Xanthocorus by the following combination of characters: body almost circular, pronotum black with anterior angles and anterior margin yellow; elytra yellow, only elytral lateral margins of elytra black (Fig. 2 a–c); apex of penis bifurcate, penis guide slightly asymmetrical, parameres stout (Fig. 2 e–h).

Description.

TL: 5.53-5.92 mm, TW: 5.11-5.30 mm, TH: 2.80-2.88 mm, TL/TW: 1.08-1.12, PL/PW: 0.49-0.50, EL/EW: 0.97-0.99.

Body almost circular, moderately convex. Head yellow with black vertex in male, entirely black in female. Mouthparts and antennae brown, sparsely covered with short, greyish pubescence. Pronotum black, only anterior angles and anterior margin yellow. Scutellum black. Elytra yellow, only elytral bead black (Fig. 2 a–c). Underside black except inner part of elytral epipleura yellow and abdominal ventrites brownish black, sparsely covered with short, greyish pubescence.

Head relatively large, 0.50 times pronotal width, punctation on frons large and densely distributed, 0.5-1.5 diameters apart, surface polished between punctation. Eyes approximately oval, densely faceted, interocular distance 0.54 times head width (Fig. 2c). Pronotum 0.54 times elytral width, pronotal punctation large and densely distributed, smaller than those on head, 1.0-2.0 diameters apart, surface polished between punctation. Punctation on elytra moderately large and densely distributed, 1.0-2.0 diameters apart, similar to those on pronotum. Prosternal process narrow with sides parallel. Posterior margin of abdominal ventrite 5 and 6 slightly emarginate medially in male (Fig. 2d).

Male genitalia: penis slender, penis capsule with short outer and inner arms, apex of penis bifurcate with membranous appendage (Fig. 2 e–f). Tegmen stout with penis guide slightly asymmetrical in ventral view and widest at base with sides parallel from base to 1/2 length, then gradually converging to blunt apex in lateral view. Parameres stout, distinctly longer than penis guide, densely covered with long setae at inner surfaces and apices with group of long setae in lateral view (Fig. 2 g–h).

Female genitalia: coxites distinctly elongate, approximately triangular (Fig. 2i).

Material examined.

China: Jiangxi Prov: 2 males and 1 female, Luofu village, Jinggangshan County, [26°65.41'N; 114°22.49'E], ca 763m, 18.ix.2004, Wang XM leg; 1 female, Jingzhu Mountain, Jinggangshan County, [26°37.95'N; 114°08.98'E], ca 1142m, 22.ix.2004, Wang XM leg.

Distribution.

China (Gansu, Zhejiang, Jiangxi, Fujian, Yunnan) (Fig. 5).

Remarks.

The Chinese specimens of this species studied were identical with the illustrations and descriptions of adult and male genitalia given by Miyatake (1970).