1a. Hairs on gaster with plumose (feathery) tips (view obliquely at 50-100×) A. plumopilus
1b. Hairs on gaster not plumose 2
2a. Petiolar scale sharp 3
2b. Petiolar scale blunt 5
3a. Hairs on body fine, thin, wispy; gular hairs short A. sublabers
3b. Hairs on body and/or gula not as above 4
4a. Hairs all over gaster, gular hairs long A. claviger
4b. Hairs all over on 1st tergite; only on edges of 2nd and 3rd tergites; gular hairs few A. interjectus
5a. Very hairy all over; many gular hairs A. latipes
5b. Hairs on propodeum denser than elsewhere; gular hairs few, short A. murphyi
Reference: Wing, M. W. 1968. Taxonomic revision of the nearctic genus Acanthomyops (Hymenoptera: Formicidae). Memoirs of the Cornell University Agricultural Experiment Station 405: 1-173.
Additional information from conversation with Stefan Cover (MCZ), 11/15/2006
Acathomyops latipes
