Hochiminhus tamdaoensis Dietrich & Nguyen & Pham 2020, n. sp.

Hochiminhus tamdaoensis n. sp.

(Figures 4 A–O, 11M)

Description. Length of male 4.3 mm; female 4.4 mm. Crown with two pairs of small apical brown spots, two pairs of larger orange maculae on disc and pair of small brown spots posterolaterad of ocelli; face with frontoclypeus mostly orange, ocellocular area, anteclypeus, lorum and lower part of gena mostly black; pronotum with large orange-brown area medially and four dark brown posterior submarginal maculae; mesonotum and scutellum mostly yellow, basal triangles slightly infuscated; forewing with round black spot near base and larger black macula at apex of clavus, costal margin with black maculae at base, midlength and near apex, band of bright yellow opaque pigment present between basal and medial macula; thoracic pleurites mostly dark brown to black; front and middle femora and hind tarsomeres I and II mostly black.

Apex of male pygofer lobe unpigmented and concavely emarginate. Style with three distal processes: one short, rounded preapical process extended mesad; one longer lateral spine extended posterodorsad; and one larger distal spine with knifelike dorsal margin extended dorsomesad and crossing counterpart on other style forming X in ventral view.

Female sternite VII with posterior margin broadly and shallowly emarginate, bordered with fuscous.

Etymology. The species name refers to the type locality.

Material examined. Holotype male, VIETNAM: Vinh Phuc, Tam Dao, 21.4561ºN 105.6501ºE, 983m, 10 July 2019, C.H.Dietrich, Hg vapor light in forest, VN19-7-1 [VNMN]. Paratype, 1 female, VIETNAM: Vinh Phuc, Tam Dao 21.4509ºN 105.6325ºE, 741m, 13 July 2019, C.H.Dietrich, sweeping understory in 2º pine forest, VN19-8-2 (INHS).