Euxestoxenus thomasi Ślipiński, 2020

Ślipiński, Adam, 2020, A new species of Euxestoxenus Arrow (Coleoptera: Euxestidae) from Thailand, Insecta Mundi 2020 (838), pp. 1-4 : 2

Euxestoxenus thomasi Ślipiński , new species

( Fig. 1–8 )

Diagnosis. This species can be easily separated from the only known Oriental species, E. striatus in having 10-segmented antenna and the dorsal surfaces devoid of striae and setae. Of the three African glabrous species, E. thomasi is most similar to E. nudus John but differs by a shorter and more compact antennal segments, rounded antennal club and strongly flattened and expanded femora and tibiae.

Description. Length 1.2–1.4 mm; body elongate oval ( Fig. 1 ), 1.4–1.5 times longer than wide, moderately convex; colour light brown to dark brown; dorsal surfaces smooth and shiny; vestiture apparently absent, very short hairs barely traceable under 100× magnification. Eyes somewhat reduced, coarsely facetted ( Fig 2 ). Clypeus coarsely punctate and setose; punctures about 0.5 times as large as eye facets and 1 diameter apart; interspaces smooth and shiny. Frons slightly convex; punctures 0.5–0.8 times as large as these on clypeus, 1–2 diameters apart; interspaces smooth and shiny. Antenna 10-segmented ( Fig. 3 ); antennal club small, transverse, diameter at broadest point about 0.3 length of pronotum. Pronotum transverse, length 0.45–0.50 times width, widest at base, weakly narrowing anteriorly; anterior angles blunt; anterior margin arcuate at middle; lateral sides weakly curved, lateral carina smooth with complete but narrow bead entirely visible from above; pronotal base arcuate not distinctly prominent medially, slightly overlapping scutellum; prothoracic hypomeron concave but without delimited cavity ( Fig. 6 ). Disc convex, punctures small, mostly as large as those on frons or slightly smaller, 2–3 diameters apart, interspaces smooth and shiny. Scutellum as broad as long, triangular, glabrous. Elytra about 1.1–1.2 times longer than wide, widest at basal third, jointly rounded apically; margins narrow, invisible at apical fifth from above. Elytron without striae, surfaces with fine irregular punctures ( Fig. 4 ), punctures as large or slightly larger than those on pronotum 1–3 diameters apart; interspaces smooth, shiny. Femora and tibiae broad ( Fig. 5, 7 ). Aedeagus with weakly asymmetrical tegmen and penis with fused basal struts ( Fig. 8 ).

Material examined. Holotype: “ Thailand, Chiang Rai, 10 km W Wiang Pa Pao, Ban Huay Ya Sal , 780 m, 28.i.1988, P. Schwendinger ” ( MHNG) . Paratypes; “ Lampoon [Lamphun?], 16.viii.1979, pied arbre, J. Roberts ” (4, MHNG; 2, ANIC) .

Etymology. The species is named after the late Dr. Michael C. Thomas for his contributions to beetle taxonomy.

Figures

Figures 1–8. Euxestoxenus thomasi sp.nov.1) Dorsal habitus.2) Head ventral.3) Antenna. 4) Elytron.5) Anterior leg. 6) Prothorax ventral. 7) Pterothorax and abdomen, ventral. 8) Aedeagus.