Oxyporus bifasciarius, Zheng, Li, and LiU, 2010

Yan, Xiang-Hui & Zheng, Fa-Ke, 2023, First Description of the Male of Oxyporus bifasciarius Zheng, Li, and Liu (Coleoptera: Staphylinidae: Oxyporinae), The Coleopterists Bulletin 77 (1), pp. 24-27 : 24-26

OXYPoRUS BIFASCIARIUS Zheng, Li, and LiU ( Fig. 1 )

Oxyporus bifasciarius Zheng et al. 2010: 296 ; Li et al. 2018: 98; Li et al. 2019: 235; Li 2020: 149. Type locality: China (Yunnan).

DescriPtion of Male. Head subquadrate, wider than long, widest at anterior one-third of temple, gently arcuate behind eyes, posterior angles obtuse; eyes moderate in size, prominent. Antenna stout, slightly longer than head; antennomere 1 fusiform, widest in apical one-third; antennomeres 2 and 3 cylindrical; antennomere 4 slightly dilated apically; antennomere 5 slightly dilated apically, slightly flat; antennomeres 6–10 flat, more or less oblong, with dense pubescence laterally; antennomere 11 bulletshaped. The length/width ratio of antennomeres 1–11 as follows: 3.0, 1.5, 1.7, 1.5, 1.0, 0.7, 0.6, 0.5, 0.5, 0.4, 1.0; relative lengths of antennomeres: 30.0, 15.0, 15.0, 15.0, 15.0, 15.0, 15.0, 12.5, 12.5, 10.0, 20.0; and relative width: 10.0, 10.0, 9.0, 10.0, 15.0, 20.0, 22.5, 22.5, 25.0, 25.0, 20.0.

Pronotum wider than long, lateral margins subarcuately narrowed anteriad and posteriad, widest at approximately anterior third; disc smooth, transversely depressed before middle, two vague post-median depressions near middle of posterior margin; lateral sides shallowly depressed in the basal one-half, well expanded to the widest point, narrowed basally, with two setae on the apical one-fourth, one-half, and three-fourths; anterior margin feebly emarginated at the middle, with two setae near corners; posterior margin arcuate. Scutellar shield impunctate, apex rounded, surface almost smooth. Elytra subquadrate, wider than long, slightly dilated apically; disc with several irregular punctures, with two punctulate striae, outer stria is present from the anterior one-fifth to three-fourths and feebly oblique, and inner stria is present from the anterior one-fourth to near the posterior margin and longitudinal; lateral and posterior margins with several setae. Basisternum asetose. Metaventrite sparsely clothed with short, colorless pubescence, inner coxal process truncate at the apex. Legs simple, rather stout. Hind wings developed.

Abdomen covered sparsely with minute punctures and indistinct alutaceous microsculpture; tergites III and IV each with a pair of pruinose spots in middle; tergite VIII arcuate at the caudal margin, with approximately 23 setae; sternite VIII broadly, shallowly emarginate at posterior margin, with approximately 38 setae ( Fig. 1B ).

Aedeagus robust, weakly asymmetrical; median lobe barely twisted, with a basal capsule approximately two-thirds the length of the apical lobe; apical lobe narrowest at the basal one-fifth, thence feebly dilat- ed toward the widest point of the apical one-fifth, broadly and shallowly emarginate at the apex in ventral view; parameres slender, approximately one-third the length of the apical lobe, gradually narrowed apicad ( Figs. 1D–F ); endophallus with twin-coned spherical dorsal lobe covered with medium-sized denticles, transverse ventral lobe covered with tiny granulation; apical distal lobe membranous, slightly bent ventrad, approximately equal width at base and apex, with one pair of relatively short dorsal and ventral spiculae, adjunct to common basal sclerotization ( Figs. 1G–I ).

Measurement. Male (n = 17). BL: 7.15–8.59 mm (8.06 ± 0.45 mm); FBL: 4.60–5.50 mm (5.13 ± 0.28 mm); HL: 1.22–1.79 mm (1.56 ± 0.15 mm); HW: 1.71–2.20 mm (1.97 ± 0.14 mm); TL: 0.72–1.01 mm (0.92 ± 0.10 mm); AL: 1.21–1.89 mm (1.65 ± 0.20 mm); PL: 1.21–1.50 mm (1.43 ± 0.10 mm); PW: 1.72–1.92 mm (1.76 ± 0.09 mm); EL: 2.02–2.32 mm (2.14 ± 0.08 mm); EW: 2.41–2.78 mm (2.65 ± 0.15 mm); EYL: 0.49–0.60 mm (0.53 ± 0.05 mm); AW: 2.22–2.60 mm (2.47 ± 0.12 mm); ESL: 1.51–1.98 mm (1.65 ± 0.15 mm); HL/HW: 0.67–0.88 (0.80 ± 0.06); AL/HL: 1.00–1.13 (1.06 ± 0.06); PL/PW: 0.71–0.88 (0.80 ± 0.05); HW/PW: 1.06–1.17 (1.12 ± 0.04); EL/EW:0.75–0.88 (0.81 ± 0.04); EW/PW:1.41–1.56 (1.48 ± 0.05).

Remarks. The species is very distinctive, the head and pronotum being black and abdominal tergites 3–7 with two slightly broad, black, longitudinal fasciae ( Fig. 1A ). The male is similar to the female, but with the head broader than the pronotum (ratio 1.12 ± 0.04; the head approximately as wide as the pronotum in the female), the mandibles longer, and posterior margin of sternite VIII slightly emarginate (posterior margin slightly arcuately produced in the female, Fig. 1C ).

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Figures

Fig. 1. Oxyporus bifasciarius. A) Male, dorsal view, B) Male, sternite VIII, C) Female, sternite VIII, D) Aedeagus, ventral view, E) Aedeagus, lateral view, F) Aedeagus, dorsal view, G) Endophallus, ventral view, H) Endophallus, lateral view, I) Endophallus, dorsal view. Scale bars: A = 2.0 mm; B–F = 0.2 mm; G–I = 0.1 mm.