We undertook this study in order to determine the composition, distribution and general ecology of the ants of California desert regions. Since some sort of artificial
boundaries had to be established, we adhered to those of the California Desert Plan Program, Bureau of Land Management, U.S. Department of the Interior, an area of approximately 256,730 hectares (40,114 square miles) (Map 1). The ant fauna of no
comparably large North American hot desert area has ever been so surveyed. The increasingly important role of ants as subjects for ecological studies in arid lands renders a study such as this one necessary.
     The standard reference work for systematics of ants in the United States has been "Ants of North America" by William S. Creighton (1950). This work, the first modern study of a major ant fauna, is now very much in need of revision. Several large genera with desert representation have been revised, and Creighton's keys are no longer pertinent for those genera. Furthermore, the experience of the senior author has been that those keys are very difficult for the nonmyrmecologist.
      Of T. W. Cook's The Ants of California (1953) we have little good to say. The work was hopelessly outdated at the time of its publication. Keys, as such, are wholly lacking. The bulk of the text, including the distribution records, is gleaned from previously published works of other authors. Often these earlier records were, as we now know, based on misidentified specimens and therefore Cook merely compounded the difficulties for the unwary. The illustrations frequently are erroneous or irrelevant. Throughout the text which follows we have made no further mention of this myrmecological curiosity, except to note the proper synonymic placement for a couple of the forms described as new by Cook.
     The only other principal reference work is The Ants of Deep Canyon by George C. and Jeanette Wheeler (1973). Since the Deep Canyon transect utilized by the Wheelers extends from low desert to coniferous forest, it includes many nondesert species. And, since it is a restricted study, its applicability to the desert, as a whole, is limited. Nonetheless, it ranks as a work of major importance, and has been much used by investigators of desert ants. The keys, though based solely on worker castes, are quite workable and are supplemented by pertinent illustrations. The present study, encompassing as it does, a far more extensive area, naturally deals with more species. Even so, the pertinence of The Ants of Deep Canyon to the entire California desert region is impressive. The Wheelers include 19 genera in the desert part of their study with a total of 52 species. In our much larger area we have 26 genera and 99 species (Appendix 1). Thus, they dealt with 73% of our genera and 53% of our species. When allowance is made for those species which barely enter our area, with only one or two records, their species treatment is about 60% of ours.


Next