Thinodromus (s.str.) mamasensis 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 : 45

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

Figs 4–6 .

MATERIAL. Holotype, ♂, Indonesia, Sulawesi, Mamasa County: with labels “S Sulawesi, 8 km W Mamasa, 950 m 119.20.32E 2.56.13S 18.–21.Jul 1999, Bolm lgt.” ( SMNS).

DESCRIPTION (holotype). Length 3.5 mm. Colouration dark-brown, legs, 1–3th, 9–11th segments of antennas and apex of elytra brown. Integument is slightly shiny, body with rather short, 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 25:39. 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. 2 ). Head surface with clearly, finely and dense punctation. Diameter of punctures is about 2.0 times smaller than the eye facet. Distances between punctures much smaller than their diameter, interspaces smooth, slightly shiny ( Fig. 2 ). Antennae long, with lengths of all antennal segments noticeably or significantly longer than their width ( Fig. 2 ).

Pronotum heart-shaped, reaches its greatest width after 2/ 3 its length from base, then narrowed ( Fig. 2 ). Ratio of pronotum length to its maximum width is about 37:46. Surface of pronotum with clearly, finely and dense punctation. Diameter of punctures is about 2.0 times smaller than the eye facet. Distances between punctures much smaller than their diameter, interspaces smooth, slightly shiny ( Fig. 2 ). Base of pronotal disc with distinct horseshoe-shaped depression ( Fig. 2 ); central part of disc with 2 symmetrical weakly developed oval depressions.

Ratio of length of elytra to their combined width is about 63:69. Elytra with clearly, finely and dense punctation. Diameter of punctures is about 1.5 times smaller than the eye facet. Distances between punctures much smaller than their diameter, interspaces smooth, slightly shiny ( Fig. 1 ).

Abdomen with fine and dense punctation, slightly shiny.

Aedeagus of a characteristic structure (Figû 5–6).

Female. Unknown.

REMARKS. The species is similar to Thinodromus (s.str.) shavrini Gildenkov, 2020 [ Gildenkov, 2020] described from the Philippines. It is distinguished by a noticeably smaller and more dense punctation of the head, pronotum, and elytra. Reliably distinguished by the structure of the aedeagus ( Figs 5–6 vs Gildenkov, 2020: Figs 10, 11).

DISTRIBUTION. Sulawesi ( 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.