Microdytes sekaensis Okada & Wewalka sp. nov.

Figs 5, 10, 15

Type locality.

Thailand, Bueng Kan Province, Seka District, Ban Tong, 18°08'16"N, 103°59'35"E, alt. 190 m.

Type material.

Holotype (THNHM): ♂, "THAI: Bueng Kan Seka Dist., Ban Tong St. 206 (alt. 190 m) 28.XII.2020 R. Okada leg. \ HOLOTYPE Microdytes sekaensis sp. nov. Okada & Wewalka 2022" [printed red label]. Paratypes (37 exs.): 1♂, with same data as the holotype (CGW); 36 exs., Laos, Bolikhamsay Province, Nam Kading NPA, Tad Paloy campsite, 18°21-23'N, 104°09'E, alt. 250-400 m, 24.-28.V.2011, NHMB Basel Laos 2011 Expedition, M. Geiser, D. Hauk, A. Phantala & E. Vongphachan leg. (CGW, CRO, NMB, NMP). All paratypes are provided with printed red paratype labels.

Diagnosis.

Microdytes sekaensis sp. nov. resembles M. hainanensis Wewalka, 1997 and M. schwendingeri Wewalka, 1997 (Figs 34, 40B) in habitus and size but differs by elytral markings and clypeus not bordered. Size and coloration of M. sekaensis sp. nov. is also similar to those of M. gabrielae Wewalka, 1997 (Fig. 23), but it is distinguishable from the latter by the more rounded-oval body and finely and sparsely punctured ventral surface.

Description.

Measurements. TL = 1.34-1.36 mm (1.36 mm), TL-h = 0.92-0.93 mm (0.93 mm), MW = 0.99-1.01 mm (1.01 mm), TL/MW = 1.35-1.36 (1.35). Body broadly oval, strongly convex (Fig. 5).

Coloration. Head yellowish brown. Pronotum yellowish brown, along posterior margin narrowly dark brown. Elytron reddish brown to dark brown with two yellowish brown spots: one basal spot not reaching base, one anterior lateral spot continuing along the lateral margin to a post-median lateral spot and a transverse spot near apex, also with a round median spot near suture (Figs 5, 10). Ventral surface predominantly yellowish brown. Legs, antennae and palpi yellowish brown.

Sculpture and structure. Head very finely and sparsely, slightly irregularly punctured; entirely and distinctly microreticulate; clypeus not bordered. Pronotum quite irregularly, finely, and sparsely punctured on the disc, additionally with coarser punctures at medial part of posterior margin; without microreticulation; lateral margins finely bordered, regularly rounded. Elytron fairly finely, regularly, and moderately densely punctured, progressively finer and sparser towards lateral margin; two longitudinal rows of punctures moderately distinct; highly polished and shining; without microreticulation. Ventral surface: metacoxae and metasternum finely and sparsely punctured, epipleura and abdomen almost without punctures; without microreticulation.

Male. Median lobe of aedeagus in ventral aspect slightly tapered from base to apex and narrowly constricted before apex, apex spoon shaped (Fig. 15A); in lateral aspect slightly curved with an arrowhead shaped apical expansion (Fig. 15B). Paramere narrowly trapezoid in lateral aspect (Fig. 15C, D).

Female. Without secondary sexual characters. Sclerotized spermatheca not found.

Variation.

Variation of markings is shown in Fig. 10.

Etymology.

This species is named after the district name of the type locality.

Habitat.

This species was collected in the remaining water pools in a dried-up stream which had a sandy bottom with rich leaf deposits (Fig. 47).

Distribution.

Thailand: Bueng Kan Province; Laos: Bolikhamsay Province.