Pogonomyrmex laticeps -group

Workers in the P. laticeps -group are diagnosed by the following characters: (1) first gastral tergum lacking striae, (2) head broader than long, (3) interrugae on cephalic dorsum and dorsum of mesosoma smooth to moderately coriarious, weakly shining to shining (granulation and/or punctation absent) or rugae incised, interrugae about as wide as rugae, (4) superior propodeal spines well-developed, and (5) inferior propodeal spines poorly-developed or lacking. The mostly smooth interrugae appear to be the best character to diagnose P. laticeps and P. tinogasta . All three species have brachypterous queens, diagnosed by: (1) poorly-developed mesoscutum, its anterior margin barely surpassing the humeral shoulders of pronotum, (2) pronotum enlarged, and (2) in profile, the pronotum rises at an approximately 45o angle to meet the mesoscutum.