Simulium (Gomphostilbia) parahiyangum Takaoka & Sigit, 1992

Simulium (Gomphostilbia) parahiyangum Takaoka & Sigit, 1992: 135 –142 (Female, male, pupa and larva).

Specimens examined. Seven females, nine males (all reared from pupae), and six mature larvae, collected from a slow-flowing stream (width 1.0 m, depth 5–10 cm, bottom sandy, water temperature 18.0˚C, shaded, elevation 80 m, 19˚30’46.589”N/105˚09’10.470”E), Chau Dinh, Quy Chau, Nghe An Province, northern Vietnam, 11-XII-2015, by H. Takaoka, M. Sofian-Azirun, C.D. Chen & K.W. Lau.

Distribution. Java, Sumatra, Malaysia, Thailand, Assam and Vietnam (Nghe An) (New record).

Remarks. The male of this species collected from Vietnam differs from that of S. (G.) parahiyangum from Java by the number of upper-eye facets in 14 vertical columns and 14 (rarely 15) horizontal rows (in 17 vertical columns and 15 horizontal rows in the original description) (Takaoka and Sigit 1992).