Pselaphodes olexai sp. nov.

(Figs 10A, 11)

Type material (1 specimen). HOLOTYPE: VIETNAM: ♂, ‘ Tam Dao, 20-27.6, N. VIETNAM, A. Olexa, 1990’ (MHNG) .

Diagnosis. Male length 3.08 mm. Antennomere 9–11 elongate and forming distinct club, antennomere 9 with large disc-like protuberance near apex. Protrochanter with hook-like ventral spine, profemur strongly expanded at middle, with long, thin ventral spine, protibia with broad and apically truncate projection; mesotrochanter with acute ventral spine. Horn-like metaventral processes short and apically blunt. Median lobe of aedeagus asymmetric, narrowing and curved rightwards at apex in dorsal view; parameres broad; endophallus composed of two elongate sclerites. Female unknown.

Description. Male (Fig. 10A). Body length 3.08 mm. Head slightly wider than long, HL 0.56 mm, HW 0.59 mm; eyes prominent, each composed of about 42 facets. Antennomeres 2–8 similarly moniliform, antennomeres 9–11 (Fig. 11A) forming distinct club, antennomere 9 with large disc-like protuberance near apex, antennomere 10 subcylindrical, antennomere 11 sub-oval, narrowing from middle toward apex. Pronotum (Fig. 11B) slight longer than wide, PL 0.61mm, PW 0.57 mm, with lateral margins rounded and narrowing apically at apical 1/3. Elytra much broader than long, EL 0.81 mm, EW 1.10 mm. Horn-like metaventral processes (Fig. 11C) short and straight, blunt at apices. Protrochanter (Fig. 11D) with hook-like ventral spine, profemur strongly expanded and with acute and long ventral spine near middle, protibia (Fig. 11E) with large, apically truncate projection before apex; mesotrochanter (Fig. 11F) with short ventral spine; mesofemur (Fig. 11F), metatrochanter and metafemur (Fig. 11G) simple. Abdomen broad at base and narrowed apically, AL and AW 1.0 mm. Sternite 7 (IX) (Fig. 11H) hemi-membranous, roundly elongate. Aedeagus (Figs 11I –E) 0.55 mm long, median lobe asymmetric dorso-ventrally, narrowing and curved rightwards at apex in dorsal view; parameres each with two long and two short apical setae; endophallus with one elongate sclerites at middle and another elongate one at base. Female. Unknown.

Comparative notes. Antennomere 9 with a distinct disclike protuberance, thickened protibia with a large, apically truncate projection, and broad profemur of the male collectively provide a ready separation of P. olexai sp. nov. from all known congeners.

Etymology. The new species is named after the Czech entomologist Aldo Olexa, collector of the holotype.

Distribution. Northern Vietnam.