Thinodromus (s.str.) kelabitensis Gildenkov, 2021

Gildenkov, M. Yu., 2021, Two new species of the genus Thinodromus Kraatz, 1857 from the Islands of Borneo and Sulawesi (Coleoptera: Staphylinidae: Oxytelinae), Russian Entomological Journal 30 (1), pp. 43-46 : 43-45

Thinodromus (s.str.) kelabitensis Gildenkov , sp.n.

Figs 1–3 .

MATERIAL. Holotype, ♂, Malaysia, state Sarawak: with labels “MAL., Sarawak 1993 Kelabit HL, 5 km E Bario Pa Ukat , 27.2., 1000m, leg. M. Jäch (16)” ( NHMW). Paratype: 1♂ “MAL., Sarawak 1993 Kelabit HL. Bareo Pa Ukat, 27.2., 1000m, leg. H. Zettel (12)” (cMG) .

DESCRIPTION (holotype). Length 3.9 mm. Colouration dark brown; legs, 1–8th segments of antennae brownish; The 9–11th segments of the antennae are yellow-brown. Integument is quite shiny, body with fairly long light-coloured seta. Head transverse, with a wide base, ratio of its length (from posterior margin of head to anterior margin of clypeus) to maximum width is about 25:41. Neck constriction is well expressed. Eyes large, convex, occupying almost entire lateral side of head; temples almost indistinct, the head has the largest width in the eye area ( Fig. 1 ). Head surface with clearly, rather finely and dense punctation. Diameter of punctures is slightly smaller than the eye facet. Distances between punctures slightly smaller than their diameter, interspaces smooth, shiny ( Fig. 1 ). Antennae long, with lengths of all antennal segments noticeably or significantly longer than their width ( Fig. 1 ).

Pronotum heart-shaped, reaches its greatest width after about 2/3 of the length measured from the base, then narrowed ( Fig. 1 ). Ratio of pronotum length to its maximum width is about 39:47. Surface of pronotum with clearly, rather finely and dense punctation. Diameter of punctures is slightly smaller than the eye facet. Distances between punctures slightly smaller than their diameter, interspaces smooth, shiny ( Fig. 1 ). Base of pronotal disc with distinct horseshoe-shaped depression ( Fig. 1 ); central part of disc with 2 symmetrical distinct oval depressions.

Ratio of length of elytra to their combined width is about 66:69. Elytra with clearly, rather finely and dense punctation. Diameter of punctures is slightly more than the diameter of an eye facet. Distances between punctures slightly smaller than their diameter, interspaces smooth, shiny ( Fig. 1 ).

Abdomen with fine and sparse punctation, shiny.

Aedeagus of a characteristic structure ( Figs 2–3 ).

Female. Unknown.

REMARKS. The species is similar and, apparently, close to Thinodromus (s.str.) shavrini Gildenkov, 2020 [ Gildenkov, 2020], described from the Philippines. It is distinguished by a noticeably larger and sparser punctation of the head, pronotum, and elytra, more shiny integument, and a much sparser punctation of the abdomen. Reliably distinguished by the structure of the aedeagus ( Figs 2–3 vs Gildenkov, 2020: Figs 10, 11).

DISTRIBUTION. Borneo ( Fig. 7 ).

ETYMOLOGY. The species is named for its geographical distribution.

Figures

Figs 1–6. Thinodromus spp., holotypes, males: 1–3 — Thinodromus (s.str.) kelabitensis, sp.n.; 4–6 — Thinodromus (s.str.) mamasensis, sp.n.; 1, 4 — habitus, dorsal view; 2–3, 5–6 — aedeagus; 2, 5 — ventral view; 3, 6 — lateral view. Scale bar: 0.25 mm. Рис. 1–6. Thinodromus spp., голотипы, самцы: 1–3 — Thinodromus (s.str.) kelabitensis, sp.n.; 4–6 — Thinodromus (s.str.) mamasensis, sp.n.; 1, 4 — внеШний вид, сверху; 2–3, 5–6 — Эдеагус; 2, 5 — сниЗу; 3, 6 — сбоку. МасШтаб: 0,25 мм.

Fig. 7. Distribution of Thinodromus: T. kelabitensis, sp.n. (black circle) in Borneo and T. mamasensis, sp.n. (white circle) in Sulawesi. Рис. 7. Распространение Thinodromus: T. kelabitensis, sp.n. (черный круг) на Борнео и T. mamasensis, sp.n. (белый круг) на Сулавеси.