Bolitogyrus nanus Brunke

Brunke, Adam J., 2017, A revision of the Oriental species of Bolitogyrus Chevrolat (Coleoptera, Staphylinidae, Staphylininae), ZooKeys 664, pp. 1-97 : 58-59

Bolitogyrus nanus Brunke sp. n. Fig. 17 K–L, 20C (map)

Type locality.

Mawsynram-Balat Road, Khasi Hills, Meghalaya, India.

Type material.

Holotype (♂, MHNG): INDIA, Meghalaya, Khasi Hills, 1000m, Mawsynram-Balat, Besuchet-Löbl, 27.X.78, [1978] [printed] / Cyrtothorax spec. det. M. Uhlig 1982 [written] / Cyrtothorax vulneratus Smetana det. 1986 [written] / HOLOTYPE Bolitogyrus nanus Brunke, des. A. Brunke 2017 [red label] / AJB0000431 [identifier label].

Diagnosis.

This species can be distinguished by the following character states: head entirely dark; elytral disc dark with pale markings extending halfway to epipleural margin (Fig. 5G); pronotal margin at its widest point no more than three lateral puncture widths wide but still distinctly expanded at hind angles; forebody less than four millimeters; apex of median lobe with double-toothed carina or ‘lip’ (Fig. 17L); paramere with only simple rows of peg setae and without dense field (Fig. 17K).

Description.

Measurements ♂ (n = 1): HW/HL 1.40; PW/PL 1.29; EW/ EL 1.23; ESut/PL 0.84; PW/HW 1.01; forebody length 3.5 mm.

Extremely similar to B. khasiensis and differing only in the following: medial and lateral elytral markings more broadly connected, pale area of epipleuron not restricted to humeral spot, pale in up to entire basal half; pronotum slightly more transverse; elytral suture relatively longer than pronotum at middle; forebody distinctly shorter and thinner; median lobe in parameral view with apex distinctly acuminate and acute, apex with folded, double-tooted carina (Fig. 17L); paramere with sparse and simple rows of peg setae placed close to margin, removed from margin only at base of rows (Fig. 17K). Female unknown.

Distribution.

Figure 20C. Known only from the Khasi Hills of Meghalaya.

Bionomics.

The holotype was collected in October at 1000 m.

Etymology.

The species epithet refers to the fact that this species is the smallest known in the Oriental fauna at 3.5 millimeters in forebody length.

Comments.

Bolitogyrus nanus is extremely similar to allopatric B. himalayicus from West Bengal but is slightly smaller and the apex of the median lobe bears a double-toothed carina and the paramere lacks the dense apical field of peg setae.