Katydids and Bush-Crickets: Reproductive Behavior and Evolution of the Tettigoniidae. Darryl T. Gwynne. xiv + 317 pp. Comstock Publishing Associates (a division of Cornell University Press), 2001. $45.
If you have wondered, as I have, how katydids got their name, you will find the answer (a blend of history and onomatopoeia) in Darryl T. Gwynne's Katydids and Bush-Crickets, together with a wealth of other entomological folklore and a broad overview of the biology of the orthopteran family Tettigoniidae. The thread of Gwynne's lifetime of research binds together virtually all that is interesting about members of this group.
With a few obvious exceptions, katydids—also called long-horned grasshoppers (bush-crickets in Europe)—are less well known than other members of the grasshopper/cricket order Orthoptera. This is because the tettigoniids are seldom seen: Most of the more than 6,000 species are nocturnal, and they are nearly invisible as they hang out in the foliage of their host plants during the day. However, unseen male katydids throughout the world acoustically enrich warm summer nights with their serenades. Despite their relative obscurity, the tettigoniids have attracted the interest of a small but devoted cadre of highly productive behavioral ecologists whose work (featured here) has dramatically advanced our understanding of acoustical communication in insects and the operation of sexual selection on males and females of all animal species.
A truly extraordinary katydid is Anabrus simplex, the Mormon cricket. Members of this species are diurnal, voracious and gregarious; they are known to march in astronomical numbers across several U.S. western states. In 1848, huge bands of them invaded the crops of the newly arrived Latter-day Saints in the Great Salt Lake region of Utah. The Mormon pioneers were delivered from their "cricket plague" by a flock of divinely disoriented sea gulls, who descended on the infested wheat fields many hundreds of miles from the sea, devouring the pests and saving the harvest.
From the time of his first encounter with Mormon crickets at the dawn of his career, Gwynne was plagued by questions about their reproductive behavior. Intrigued by early entomological writings on the subject, he traveled to northwestern Colorado to observe them and found their mating behavior to be "quite different from that reported for most other species, not just other insects, but for animals in general." (Mormon cricket females are the aggressive gender in courtship.) Gwynne recognized that the study of Mormon crickets and other katydids held the potential to contribute to a general understanding of gender-specific differences in courtship patterns. This insight marked the beginning of his primary research, which broadened over time to encompass the many facets of katydid biology covered in this book.
Gwynne approaches katydid biology from evolutionary, ecological and phylogenetic perspectives. His application of the comparative method—which provides a template for understanding the evolution of certain traits by mapping the presence and absence of the traits onto a phylogeny of the group—yields some interesting hypotheses. For example, resemblance of wings to plant parts has apparently independently evolved several times in the tettigoniids, and (remarkably) complex ears in legs may have evolved twice in the order Orthoptera.
A perusal of the 37 pages of references cited reveals that the book has been exhaustively researched; this compilation of literature represents an excellent resource for anyone interested in the group. Katydids and Bush-Crickets covers all of katydid biology, with an emphasis on reproductive behavior, and will stand as a primary reference for the Tettigoniidae.
The treatise is also a treat! Gwynne's writing style is pleasant and appealing. He titillates the reader by posing major questions in the first chapter, builds mysteries and unfolds their solutions in a memorable way, and entertains with historical quips and anecdotes. The contents are well illustrated with line drawings, halftones and graphs, and a sample of the family's morphological diversity is presented in 24 thumbnail color photographs. Chapters are usefully cross-referenced.
Orthoptera specialists, general entomologists and teachers of entomology and animal behavior will value this work. It could serve as cornerstone reading for graduate seminars on sexual selection. I would not be surprised if a much broader audience of sophisticated people interested in reading natural history for pleasure also discover and enjoy the book.—Robert L. Smith, Entomology, University of Arizona, Tucson