Taxonomy of some little-understood North American ants (Hymenoptera: Formicidae) Author Shattuck, Steve Author Cover, Stefan text Zootaxa 2016 4175 1 10 22 journal article 10.11646/zootaxa.4175.1.2 887d93ae-26dc-4192-87d4-5396e561df0f 1175-5326 160280 011B74BE-40C0-4606-9354-C637F83C3E43 Acromyrmex versicolor ( Pergande, 1893 ) Atta versicolor Pergande, 1893 : 31 . Syntype workers, Calamajué (as Calamujuet) [ 29°38′N 114°25′W ], Baja California , Mexico (National Museum of Natural History) [https://www.antweb.org/specimen/CASTYPE00618]. Acromyrmex versicolor chisosensis Wheeler, W.M., 1907 : 705 . Syntype workers, Chisos Mountains [ 29°16′N 103°18′W ] , Texas ( O.W. Williams ); Terlingua [ 29°19′N 103°37′W ] , Texas ( W.M. Wheeler ) ( Museum of Comparative Zoology ) [http://mczbase.mcz.harvard.edu/guid/ MCZ :Ent:21162]. New synonym. Wheeler (1907) established A. versicolor chisosensis from a number of workers taken by Judge O. W. Williams in the Chisos Mountains of southwestern Texas , and a few workers taken by himself at Terlingua, also in southwestern Texas . His new subspecies was differentiated from typical versicolor as being distinctly lighter and more yellowish in color, with much less pronounced sculpture and in having only a few (about 12) pointed tubercles on each side of the median gastral depression. Creighton (1950) pointed out that the number of gastral tubercles varies with the size of the worker in A. versicolor and small workers of both taxa have a similar number of tubercles. Fowler (1988) was of a similar view. Although additional collections from western Texas would be helpful, an examination of current holdings of A. versicolor has failed to convince us that Wheeler’s characters represent meaningful differences. The type material of A. chisosensis seems to represent little more than pale (likely faded) and lightly sculptured individuals of A. versicolor . Pending the discovery of evidence to the contrary, A. chisosensis is best regarded as a synonym of A. versicolor . Acromyrmex versicolor is known from northern Mexico (including Baja California ) and the United States (Arizona, California, Texas) .