Oxyporus cameronianus, Senda, 2021

Senda, Yoshihiro, 2021, Revision of the genus Oxyporus Fabricius (Coleoptera: Staphylinidae: Oxyporinae) of the Malay Peninsula, Raffles Bulletin of Zoology 69, pp. 8-12 : 10-12

Oxyporus cameronianus , new species

Type series. Holotype: female (HIWA), “[ MALAYSIA; Peninsular] / Batu 19 (alt. 600 m) / nr. Cameron Highland / Daerah Batang Padang / Perak State, 7–IV–2011 / Y. Senda leg.” [printed on white label], “collected from dead tree / with mushroom” [printed on white label], “ HOLOTYPE / Oxyporus cameronianus sp. nov. / Det. Y. Senda, 2019” [printed on red label with black border].

Paratypes: 1 female (pcYS), same data as holotype ; 1 female (EUMJ), Bukit Fraser (Fraser’s Hill), 22 May 1979, T. Hatayama leg.; 1 female (KUMJ), Tapah, 18 May 1981, S. Imasaka leg.

Diagnosis. This new species is similar to O. javanus Cameron, 1936 (Java) and O. modiglianii Cameron, 1928 (Sumatra) in general appearance, but differs from these species by the parallel and longitudinal punctulate striae of the elytra (in O. javanus and O. modiglianii : elytral punctulate striae oblique and non-parallel). Also, this new species is easily distinguished from the congener, O. pendleburyi Cameron , as it has no sulci on its pronotum.

Description. Female. Colouration: Body reddish yellow, shining; head black, but labrum, labium, and maxillae except for brownish palpi yellow; antennae brownish yellow; pronotum with a black macula along anterior margin to about 1/2 point of lateral margin; elytra with a pair of round black maculae on the outer corner; metaventrite blackish in posterior 1/2; abdominal tergum V mostly black; segments VI, VII, and the basal part of VIII black.

Body robust, slightly convex dorsally. Head circular, widest at the anterior 1/3 of the temple. Eyes moderate in size, prominent. Antennae stout; antennomere I fusiform, widest at the apical 1/3; antennomeres II and III rather cylindrical; antennomere IV slightly dilated apically; antennomere V dilated apically, slightly flat; antennomeres VI to XI flat, densely pubescent in the side area; antennomeres VI to X more or less oblong, and XI bullet-shaped; the length/width ratio of each antennomere I to XI as follows: 2.1, 1.2, 1.5, 1.4, 0.7, 0.5, 0.5, 0.6, 0.5, 0.6, 1.1; relative lengths of segments: 29.0: 11.0: 12.0: 11.0: 10.0: 10.0: 10.0: 11.0: 10.0: 10.0: 17.0, and relative widths: 17.5: 11.3: 10.0: 10.0: 17.5: 23.8: 25.0: 25.0: 25.0: 22.5: 20.0.

Pronotum subhexagonal, widest at the middle; disc smooth, without any sulcus; lateral sides shallowly depressed in the basal 1/2, well expanded to the widest point, thence narrowed basally, with three setae on the apical 1/4, 1/2 and 3/4; anterior margin feebly emarginated at the middle, with two setae on the middle and near corners, respectively; posterior margin arcuate, with two setae on the middle. Scutellar shield impunctate, with an arcuate apex. Elytra subquadrate, feebly dilated apically; disc without irregular punctures, with two parallel and longitudinal punctulate striae, whose outer stria is arranged from the anterior 1/6 to 3/4 and inner stria is arranged from the anterior 1/6 to near posterior margin; lateral margin with several setae on apical 2/3; posterior margin bearing a few setae. Basisternum asetose; inner coxal process short, pointed at the apex. Metaventrite sparsely clothed with tiny colourless pubescence; inner coxal process truncate at the apex. Legs simple, rather thick.

Abdomen covered with minute punctures and alutaceous microsculpture; terga III and IV with a pair of wing folding setal patches on the middle, respectively; terga and ventrites VII and VIII with distinct shallow grooves on each posterior part; tergum VIII ( Fig. 3A ) furnished with about 24 macrosetae, arcuate at the caudal margin; ventrite VIII ( Fig. 3B ) furnished with about 36 macrosetae, barely projecting at the arcuate caudal margin; tergum IX ( Fig. 3C ) setigerous in the apical 1/3, rounded in the apex; tergum X ( Fig. 3C ) slightly longer than wide, with a few macrosetae in the apicomedial area, densely fringed with tiny setae along the arcuate caudal margin. Gonocoxites as shown in Fig. 3D ; proximal gonocoxite almost as long as distal gonocoxite, fringed with fine setae on a part of the apical margin; distal gonocoxite subtriangular, with a few setae on the outer margin, fringed with fine setae on the apical part of the inner side; styli subconical, with several setae on near apices; medial gonocoxite semirhomboidal, projected at the basal margin, with fine setae on the centre of the apical margin. Spermatheca ( Fig. 3E ) membranous, bulbous, distinctly curve in 1/2, dilated apically in the apical 1/2; spermathecal duct rather long.

Male. Unknown.

Measurement. Female (n = 3) –– BL: 7.97–8.60 mm (8.26 ± 0.32 mm); FBL: 4.61–5.10 mm (4.83 ± 0.25 mm); HL: 1.25–1.42 (1.31 ± 0.10 mm); HW: 1.65–1.92 (1.78 ± 0.14 mm); AL: 1.33–1.41 mm (1.36 ± 0.05 mm); PL: 1.51–1.67 mm (1.59 ± 0.08 mm); PW: 1.65–1.89 mm (1.75 ± 0.13 mm); EL: 1.85–2.01 mm (1.94 ± 0.08 mm); EW: 2.34–2.61 mm (2.47 ± 0.14 mm). HL/HW = 0.70–0.76 (0.73 ± 0.03); AL/FBL = 0.26–0.29 (0.28 ± 0.02); PL/PW = 0.88–0.93 (0.91 ± 0.02); PW/HW = 0.96–1.00 (0.98 ± 0.02); EL/EW = 0.77–0.80 (0.79 ± 0.01); EW/PW = 1.38–1.45 (1.42 ± 0.03).

Etymology. The species is named after Malcolm Cameron (1873–1954), who described many Oriental Oxyporus species in the early twentieth century.

Figures

Fig. 3. Oxyporus cameronianus, new species, paratype, female. A, tergum VIII; B, ventrite IX; C, terga IX (left half) and X; D, gonocoxites (right half); E, spermatheca. Scale bars: 0.5 mm for A–D; 0.2 mm for E.