Acerocnema, Becker, 1894

Iwasa, Mitsuhiro, 2021, Three new species and six new records of Scathophagidae (Diptera) from Japan with a key to the Japanese genera, Zootaxa 4981 (3), pp. 531-553 : 534

Key to the species of Japanese Acerocnema (male and females)

1. R 1 of wing with dorsal setulae on apical portion............................................................. 2

- R 1 of wing without dorsal setulae on apical portion........................................................... 3

2. Prescutum, scutum and scutellum mostly grey microtrichose, with a pair of shiny stripes on scutum ( Fig. 1 ); male surstylus anterodistally dilated ( Fig. 4 )............................................................... A. incisa sp. nov.

- Prescutum, scutum and scutellum mostly shiny; male surstylus sinuate and tapering apically (see Iwasa (2014, figs 13, 14))........................................................................................ A. sinuata Iwasa

3. Frons yellow; scutum longitudinally with a central grey microtrichose band; male surstylus filiform (see Iwasa (2014, figs 8, 9)).................................................................................. A. flavifrons Iwasa

- Frons black; scutum wholly shining; surstylus clavate (see Iwasa (2014, figs 2, 3))................ A. kishimotoae Iwasa

Figures

FIGURES 1–6. Acerocnema incisa sp. nov. 1, Male head and thorax, dorsal view (holotype); 2, Male head, left lateral view; 3, Male sternite V, ventral view; 4, Male terminalia, left lateral view; 5, Male terminalia, posterior view; 6, Female terminalia, left lateral view. Abbreviations: Head—ar, arista; fr, frontal setae; oc, ocellar setae; or, orbital setae; pal, palpus; ppd, postpedicel; prb, proboscis; vte, outer vertical setae; vti, inner vertical setae; vib, vibrissa. Abdomen - aed, aedeagus; cer, cercus; ep, epandrium; epiph, epiphallus; epipr, epiproct; hypr, hypoproct; pm, paramere; st, sternite; sur, surstylus; tg, tergite.