Sychentia vietnamensis Dietrich & Nguyen & Pham 2020, n. sp.

Sychentia vietnamensis n. sp.

(Figures 6 A–F, 11Q)

Description. Length of male 7.0 mm. Coloration white, dorsum heavily marked with complex symmetrical pattern of pale brown spots and lines forming pair of prepical diamond-shaped transcommissural marks preapically and numerous false veins on forewings.

Leg chaetotaxy and forewing venation as described for S. hainanensis Wei & Zhang (2013).

Male pygofer dorsal margin deeply emarginate near midlength, distal part of lobe with darkly pigmented dorsal falcate portion contrasting with paler ventral area. Connective with subequal to length. Style apophysis sinuate with distal part curved mesad and slightly emarginate subapically. Aedeagus in lateral view with shaft ventral margin distinctly arcuate near base then straight through rest of length, parallel sided in lateral view. shaft in posterior view very slender and parallel sided with scattered indistinct lateral teeth, apex weakly expanded and poorly sclerotized.

Etymology. The species name refers to the country of origin.

Material examined. Holotype male, VIETNAM: Ninh Binh, Cuc Phuong NP, park rd. km 29, 20.3363ºN 105.6094ºE, 350m, 8 July 2019 C.H.Dietrich, Hg. vapor light, VN19-4-1 (VNMN).

Notes. This species is very similar to S. hainanensis, described from Hainan Island, China. Both species are known from single male specimens. Further collecting is needed to confirm that these two populations represent distinct species. The Vietnamese population is here treated as a distinct species based on the following morphological differences: size distinctly smaller (length of male 7.0 mm versus 7.7 mm in S. hainanensis); pygofer dorsal margin more deeply emarginate; connective slightly wider than long (distinctly longer than wide in S. hainanensis); aedeagus with posteroventral margin distinctly arched near base and nearly straight and parallel-sided for rest of length in lateral view (evenly curved and distinctly tapered in S. hainanensis).