Acerocnema, Becker, 1894

Han, Sangjin & Shin, Seunggwan, 2025, First records of the genus Acerocnema Becker (Diptera: Scathophagidae) from South Korea, with a new species and a newly recorded species using DNA barcodes, Zootaxa 5653 (3), pp. 440-450 : 447

Key to the species of Korean Acerocnema

1 Scutum with two pairs of partial small round shiny spots along pre- and postsutural intra-alar lines ( Fig 1G ); sternite 5 Ushaped, lobes sharply triangular ( Fig 2A ); surstylus ladle-shaped in lateral view, apically enlarged and blackish ( Fig 2B ); dorsal section of cercus triangular in posterior view, ventral section of cercus slender and extended in posterior view ( Fig 2C ); hypandrium slightly arched apically not prominently developed ( Fig 2B )........................ A. saurischia sp. nov.

- Scutum with two pairs of large shiny spots between pre- and postsutural dorsocentral and supra-alar lines ( Fig 1H ); sternite 5 strongly bilobate, lobes rounded apically ( Fig 2E ); surstylus slender, parallel-sided, not tapered or enlarged apically ( Fig 2F ); dorsal section of cercus somewhat parallelogrammatic in posterior view, ventral section of cercus long and tweezer-shaped in posterior view ( Fig 2G ); hypandrium distinctively arched ventroapically and thick and stout ( Fig 2F ).... A. flavifrons (Iwasa)

Figures

FIGURE 1. Acerocnema spp., habitus lateral and dorsal views. A–B, D–E, G, Acerocnema saurischia sp. nov., habitus of male (A) and female (B), dorsal view of male (D) and female (E), left half of scutum of male (G); C, F, H, Acerocnema flavifrons, habitus of male (C), dorsal view of male (F), left half of scutum of male (H). Scale bar: 1 mm (A–F). White arrows in (G) indicate partial shiny spots on scutum of Acerocnema spp. Acerocnema saurischia sp. nov. has smaller shiny spots than those of A. flavifrons.

FIGURE 2. Male sternite 5 and terminalia of Acerocnema spp.A–D, A. saurischia sp. nov., male sternite 4 and 5 in ventral view (A); B–C, male genitalia, epandrium, cerci, surstyli in lateral view (B), in posterior view (C), adeagus in lateral view (D). E–H, A. flavifrons, male sternite 5 in ventral view (E); F–G, male genitalia, epandrium, cerci, surstyli in lateral view (F), in posterior view (G), phallus in lateral view (H). Scale bar: 0.25 mm (A, D–E, H); 0.5mm (B–C, F–G). Abbreviations: cerc—cercus; d sec cerc—dorsal section cercus; epiph—epiphallus; pgt—postgonite; ph—phallus; phap—phallapodeme; pregt—pregonite, st—sternite; v sec cerc—ventral section cercus.