Hampsonascia vanlanga sp. n.

(Figs 8, 28)

Type material. Holotype (Figs 8, 28): male, “ 06–15.XI.2013, N Vietnam, Vĩnh Phúc Province, 41 km NNW of Hanoi, Tam Dao Mt. Range, 21°23’3.34’’N 105°42’44.10’’E, edge of rainforest, 395m, local collector leg.”, gen. prep. No.: AV6409 (prepared by Volynkin) (MWM/ ZSM, ex CAV).

Diagnosis. The forewing length is 9 mm in the holotype male. The new species differs externally from its congeners in the medially paler forewing with thicker pattern elements and the paler hindwing. The male genital capsule of H. vanlanga sp. n. differs from those of other species in the dentifascia species-group in the lack of a medial costal process. Additionally, compared to H. phukha sp. n., the valva of H. vanlanga sp. n. is somewhat less curved dorsally. The vesica of the new species is similar to that of H. phukha sp. n. due to the shape of the shorter lobe of the distal diverticulum but differ in the broader subbasal chamber bearing a small lateral cluster of six tiny conical cornuti.

Distribution. The new species is known only from its type locality in Vĩnh Phúc Province in North Vietnam.

Etymology. Văn Lang was a kingdom on the territory of the modern North Vietnam.