Species Polyergus mexicanus - Western Amazon ant

Types were collected in Mexico.

Widely distributed, from the upper altitudes of central Mexican mountains, north to British Columbia, east across southern Canada to the Great Lakes Region and south to the Ozarks of Arkansas.

Open conifer and broadleaf woodlands of many types, pinyon juniper and cold desert shrublands, fields, parks, gardens, prairies. This species has the widest range of host species of all Polyergus, including F. accreta, F. marcida, F. micropthalma, F. subaenescens, F. argentea, F. podzolica, F. subsericea, F. hewitti, F. neorufibarbis, F. occulta, F. subpolita, F. lasioides, F. manni, F. neogagates, F. oregonensis & F. vinculans.

Future study may provide the wherewithal to recognize several species within the current concept of P. mexicanus. In particular, the West Coast populations formerly named 'umbratus' and 'laeviceps' seem somewhat distinctive, and another interior western morphotype could be an unnamed additional species. The latter also has some features that could indicate it is the northern part of the variation of P. topoffi. Trager's (i.e., my) morphometric and ecology-based classification failed to provide clear distinction of these three, but more material and the addition of genetic and other biochemical characters might.