Zarcosia sinuata n. sp.

(Figures 1; 3n,o; 4o; 5n; 6j)

Etymology. The species’ name refers to the marked bilateral sinuation of the base of its pronotum.

Type locality. Thailand: Mae Hong Son Province, Pai District, Mae Sae [19°07’ N 98°25’ E] .

Distribution. Thailand: Mae Hong Son Province (Figure 1).

Description. (Figure 3n,o). Body length. ♂ holotype: 2.63 mm; ♀: 2.99± 0.19 mm (n=10). Black, elongated, covered with white double pubescence.

Head. Moderately transverse, slightly wider than pronotum in both sexes. Punctation coarse and dense. Palpi dark orange, last article securiform.

Antennae. Moderately long, regularly filiform, somewhat shorter than elytra in ♂, a fourth shorter in ♀. Antennomere 3–8 more than twice longer than wide, the last three much shorter. Covered with long white hairs.

Pronotum (Figure 6j). Convex, slightly longer than wide in both sexes. Sides parallel from the base to the apical third, then converging markedly inward toward apical margin anteriorly. Densely punctuated, space between points smaller than the diameters of points. Points large and deep. Covered with double pubescence, moderately long white hairs borne from the punctation and pulverulent interspersed silver hairs. Sinuation at base particularly marked.

Elytra. Length: ♂ holotype: 1.88 mm; ♀: 1.89± 0.09 mm (n=10). Punctation similar to that of the pronotum, with slightly larger points. Covered with double pubescence, as on pronotum. Moderately convex, depressed on disc.

Legs. Rather long and thin. No sexual characters.

Aedeagus (Figure 4o). Sides regularly convergent in dorsal view, rounded at apex, with an apical button. Moderately bent in lateral view with a weak apical deflection upward.

Type material. Holotype (♂, SMNS). Thailand: Mae Hong Son Province, Pai District, Mae Sae, 19°07’ N 98°25’ E (750 m), (L. Bocák) 15.V.1993 . Paratypes. Thailand: Mae Hong Son Province, Pai District, Mae Sae, 19°07’ N 98°25’ E (750 m), (L. Bocák) 15.V.1993 (9 ♀ paratypes, SMNS; 2 ♀ paratypes, NGPC) .