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 : 532

Genus Acerocnema Becker, 1894

[Japanese name: Kuchiboso-funbae-zoku]

Acerocnema Becker, 1894 , Berl. ent. Z. 39: 154. Type-species: Cordylura breviseta Zetterstedt, 1846: 2022 , by original designation [= Cordylura macrocera ( Meigen, 1826) ].

The Palaearctic species of the genus Acerocnema were revised and defined by Ozerov (2006, 2014) and Iwasa (2014). The Nearctic fauna was recently revised by Chagnon & Sinclair (2020).

Diagnosis. Small, about 3.0-6.0 mm in body length; head rounded in profile; gena and postgena wide; male postpedicel developed and rectangular; arista bare to short-haired and not longer than maximum length of postpedicel measured on its dorsolateral surface in male; proboscis slender and sclerotized with reduced labella; palpus basally slender and dilated apically; chaetotaxy (yellow to black): 3-4 fr, 2-3 or, 1 oc, 1 vti, 1 vte, 1 poc. Thorax yellow to black and shiny or white to grey micotrichose, covered with yellowish hairs; chaetotaxy (yellow): 1-2 pprn, 2 npl, 1+2 sa, 2+3 dc, 2 pa, 1 b sc, 1 d sc, 1 ap sc,1 prepst, 1 prepm, 2-8 anepst; 1 kepst; legs slender, normally without black or stout setae; wings hyaline without any brown spots or black setae; R 1 with or without dorsal setulae on apical portion; vein A 1 not reaching wing margin. Male abdomen: enlarged apically and covered with long yellowish hairs; sternite V deeply bilobate posteriorly; surstylus articulated with epandrium and long, slender, but varied in shape; aedeagus basally chitinous and apically membranous, and sometimes whip-like; cercal plate developed and divided into complex lobes. Female abdomen: segments VI to VIII compressed; ovipositor short, strongly sclerotized and compressed posteriorly.