Key to the world subgenera of Apetaenus

1. Micropterous species with vestigial wings and halters; thorax and abdomen (in particular the latter) strikingly setose (fig. 11) or with dense, long villosity (fig. 12); fore femur in both sexes with no long setae on distal two-thirds; tarsi stumpy ............................................................................subgenus Apetaenus Eaton

-. Macropterous species (except for some rare, localized individuals of A. (Listriomastax) enderleini which exhibit brachy- and microptery) with fully developed wings and halters; thorax (except for main, long setae) and abdomen poorly setose; fore femur in both sexes with 2–4 widely spaced, very long, forward curved, postero-ventral setae on distal two-thirds; tarsi slender (more or less shortened in specimens showing wing reduction).............................................................................................................................2

2. Vein R1 bare; postpronotal seta lacking; preabdomen of female strongly physogastric, with syntergite 1+2 deeply split medially; wing reduced in some isolated specimens .......... subgenus Listriomastax Enderlein

-. Vein R1 setulose; postpronotal seta strong; preabdomen of female moderately physogastric, with syntergite 1+2 never split medially; no wing reduction .................. subgenus Macrocanace Tonnoir and Malloch