PHEIDOLE in the New World A Dominant Hyperdiverse Ant Genus
by Edward O. Wilson.
Harvard University Press, Cambridge, Mass. 2003.
Hard bound, 794 pages + CD ROM.
ISBN 0-674-00293-8. Price: US$ 125.00.

     Pheidole is, as the title makes clear, a very large genus; so, too, is this coffee table size book, the cover 9.5 x 12.25 inches! This does make the book awkward to deal with, especially on our cluttered work spaces.
     The book is dedicated to the late William L. Brown, Jr., who had initiated this study jointly with Wilson. There is a brief homage to "Uncle Bill".
     A 12-page Introduction discusses, in general terms, the genus Pheidole as it exists in the New World; Wilson recognizes 624 species, of which 337 are described as new. "Hyperdiverse", indeed. This enormous number of species is allocated to 19 species groups, with the bulk of the species placed in just five species groups.
     A brief 6-page chapter succinctly and clearly discusses the origins of hyperdiversity. Another 6 pages are given over to Glossary and Anatomy, with excellent, clear figures. Unfortunately, in this section there are a few gross errors. Bowing to long-established convention, the term "occiput" is used for the "posterior" margin of the head, considered by Wilson to be prognathous. The true occiput actually lies on the "ventral" surface, immediately posterior to the foramen. Wilson, thus, also incorrectly places the "vertex" between the frontal triangle and the "occiput". The correct term for the "occiput", sensu Wilson, is vertex and for "vertex", sensu Wilson, it is frons. The so-called "nuchal collar" is equivalent to the preoccipital carina as used by other Hymenopterists. These quibbles aside, this is a very useful section.
     Most of the remainder of the book is devoted to the systematics of the New World Pheidole. First, there is a short key to the workerless socially parasitic species. A key to the species groups, based largely on major workers follows. Pages 33-128 consist of the keys to species within each of these groups, the groups arranged alphabetically.
     A serious problem with these keys is that they are based almost exclusively on the major workers ("soldiers"). All to frequently, only minor workers are available for examination. While it is not always possible to prepare a key that will distinguish between the minor workers within a given complex, keys can be assembled that will distinguish between the complexes. From that point one is usually able to make a reasonable "best guess". But, in a few places (e.g., the key to the tristis group, couplets 100 & 101), couplets may solely utilize minor worker features.
     Another problem is that there are no accompanying figures to ease one past a difficult couplet (and there are plenty of those). This difficult is exacerbated the lack of page numbers following each species name in the key. Since the species accounts are arranged by species group, a bit of time is lost searching for the appropriate species figures. This could have been avoided by making each species group a separate chapter consisting of the key to species, followed by the individual species accounts.
     Species treatments are, as already noted, alphabetical within their respective groups. Each treatment occupies (usually) a single page. There is a note on those species with which each may be confused. This is followed by label data for the primary type, most of which had been examined by Wilson. Below this information is a set of figures, rigidly uniform throughout the systematic treatment, thus facilitating easy comparison of important features from one species to the next. Below the figures are a listing of known synonyms, depository of primary type, diagnoses of major and minor worker, and brief summaries of distribution and biology. There is sometimes a discussion of synonymies and of taxonomic decisions.
     Here, one could wish for more. Maps showing distribution would have been helpful. Again bowing to convention, the sexual forms are almost wholly ignored, even though queens often have useful diagnostic features. During the course of diversity surveys, one often collects only sexual forms, especially in light traps and Malaise traps. Again, it would have been helpful to have keys that would at least enable a researcher to get the specimens into the correct species groups, at least.
     Wilson's species concept is sometimes a bit shaky and some of the species described as new are sometimes based on single samples and are only questionably distinct. Some of the subspecies elevated to species also seem dubiously differentiated. For example, I remain unconvinced that P. jelskii is really distinct from P. fallax (of which it was an erstwhile subspecies), at least as they occur on Puerto Rico and the Virgin Islands.
     The systematic portion of this book is followed on p. 779 by a list of a dozen taxa on indeterminate status, because no type or other authentic material was available for examination.
     The 8 pages of References appears to be complete and thorough.
     There are 2 pages of Acknowledgements. Curiously, the Natural History Museum of Los Angeles County (LACM) is said to have "parts of R. E. Gregg and W. M. Wheeler Collections." This is only true in the same sense that nearly every major collection of ants in the U.S. also has parts of these collections. No notice is taken of the fact that LACM does have the personal collections of W. F. Buren, A. C. Cole, Jr., and W. S. Creighton, as well as the North Dakota and Nevada collections of G. C. & J. Wheeler.
     This treatment of the New World Pheidole is a monumental achievement by one of the World's most eminent myrmecologists and distinguished scholars. While it is not without its shortcomings (some of which are, I readily acknowledge, a matter of personal preference) this book will doubtless remain the starting point for further research on Pheidole systematics for many years to come. One shudders to contemplate the size of this genus once the Old World fauna is similarly treated! The clear concise style and excellent figures will set a standard that will challenge all future such works.

Roy R. Snelling
Natural History Museum
of Los Angeles County
900 Exposition Boulevard
Los Angeles, CA 90007