Whitney Cranshaw
Princeton University Press
2004, 656 pp.
Price: $29.95, paper
ISBN 0-691-09561-2 (paper); ISBN 0-691-09560-4 (cloth)

Whitney Cranshaw’s latest effort, a 656-page treasure trove of behavior, biology, and images of arthropods (and snails and slugs) encountered in our gardens and landscapes, is almost the ultimate guide to “backyard bugs.” In his approach, Cranshaw ventures well beyond the setting of a traditional vegetable or herb garden. His book describes the full pantheon of pest and beneficial arthropods that surround us in the home landscape. By embracing a worldview of the garden, Cranshaw vastly expands his audience and the usefulness of his book. For a reference text of this caliber, Garden Insects of North America is an extraordinary bargain at $29.95 for a paperback volume.

The book is filled with hundreds of high-quality color photographs that are invaluable additions to text descriptions of more than 1,400 arthropods. Cranshaw has gone to great lengths to solicit exceptional pictures from experts across the United States. The photographic plates far exceed typical diagnostic references, which present images of only the most commonly observed pest life stages.

Cranshaw includes close-focus views of eggs, larvae, pupae, and adult arthropods, as well as pest-feeding injury and the plant’s response to infestation. Images of adult arthropod species often include males and females. This is a great help when adults are sexually dimorphic. Among some pests, such as peachtree borers [Synanthedon exitiosa (Say), p. 465), the adult genders look very different, but actually belong to the same species. Readers from all backgrounds will appreciate several photographs that show arthropods performing characteristic behaviors that are often useful clues for identifying arthropods.

Like most first chapters that present entomology to the gardening public, Garden Insects of North America provides fundamentals of arthropod biology. But Whitney’s first chapter also includes full-color plates of signs and symptoms of arthropod-related plant injury. Plates include “Excreted and Secreted Products [of] Arthropods and Slugs,” “Body Parts Useful in Diagnosing Garden Arthropods,” “Fruit and Foliage Injuries Produced by Arthropods and Slugs,” and plant responses to “Plant Pathogens Transmitted by Arthropods.” Images in these plates show helpful clues for successfully diagnosing plant injury related to arthropods.

Unfortunately, this reference does not include representative images of nonarthropod-related plant injury. For example, accidental plant exposure to abiotic factors, herbicides, and plant growth regulators that cause abnormal growth and phytotoxic effects are often misdiagnosed by gardeners as arthropod injury. Chapter 1 would have benefited from including characteristic images of these types of plant injury.

In Chapter 2, Cranshaw briefly describes basic principles for managing garden pests. Discussion and control recommendations are segregated by arthropod feeding guild. Snails and slugs are also included within recommendations for “Leaf Chewers and Leafminers.” Cranshaw does not burden his reference with specific chemical control options. These recommendations vary regionally and are better provided elsewhere. Instead, his recommendations for pest management synthesize expert experiences across the United States and almost all control strategies include acceptable control strategies for organic systems. By presenting several options, users can select the management approach that best applies to their particular situation. Missing from Chapter 2, and indeed, from most of the text, are practical descriptions of methods that gardeners and homeowners can use to collect arthropods. This is unfortunate because these tools are often necessary to detect the presence of cryptic species and estimate the densities of pest populations.

The nine remaining chapters are divided into arthropod feeding guilds. These groupings are logical because they aptly describe pest activity or feeding damage that are first apparent to gardeners. In “Leaf Chewers” (Chapter 3), Cranshaw gives excellent treatment to sawfly species that feed across a wide range of host plants. Because sawfly larvae are often confused with caterpillars and misdiagnosis can cause management efforts to fail, the outstanding collection of adult and larval images are a great diagnostic aid. In Chapter 7, he introduces the “Gall Makers”: a fascinating guild of arthropods that also are often overlooked by many gardening references. Chapter 10, which is devoted to “Root, Tuber and Bulb Feeders,” presents several seldom-seen and cryptic species that are easily overlooked by gardeners when plants seem to “just suddenly die.”

Too commonly, references developed for public audiences fail to include scientific names of arthropods, relying only common names within the index. Cranshaw avoids this shortcoming, which makes the reference particularly valuable for intermediate enthusiasts and advanced experts. Academics may be disappointed with this as a research reference because the scientific names of arthropods do not also list the taxonomic authorities attributed with species identification.

“Beneficial Garden Arthropods” are given excellent treatment in Chapter 11. Discussion offers biological vignettes of several well-recognized beneficial arthropods, pollinators, and other key arthropods that regulate landscape pest populations. But Cranshaw also takes pains to establish the dual role that many arthropods play both as pests and beneficials in our landscapes. He describes that earwigs (Dermaptera: Forficulidae), for example, are opportunistic omnivores and feed as important predators of soft-bodied arthropods. Unfortunately for gardeners, earwigs may also supplement their diets with soft tissues of plant leaves and flower petals. Chapter 11 also provides brief but effective introductions of entomopathogens, as well as nematodes and horsehair worms, that commonly affect arthropod population dynamics.

The book includes a useful appendix of “Host Plant Genera and Associated Insects and Mites” and a 7-page glossary of related terms. If the reader could possibly want more, Cranshaw also includes a list of superb references that is subdivided according to ornamental crop type. Perhaps the greatest shortcoming of the reference is that its index does not include searchable, paginated references to host plants.

The reference is extremely up-to-date and includes numerous species that are recent introductions to parts of the United States. Photographs of new pests, such as Asian wooly hackberry aphids (Shivaphis celti in “Sap Suckers,” Chapter 6), emerald ash borers (Agrilus planipennis in “Trunk and Branch Borers,” Chapter 9), and viburnum leaf beetles (Pyrrhalta viburni in “Leaf Chewers,” Chapter 3), will be invaluable if these arthropods expand beyond their current locales.

In sum, I expect this book to become a standard desk reference for home and master gardeners, extension agents, and researchers. In fact, Cranshaw dedicates his work “to entomology educators and to the Cooperative Extension system.” We can only hope that a future “deluxe” edition might include a CD-ROM of the photographs.

William E. Klingeman
Plant Sciences Department
University of Tennessee
Knoxville, TN 37996-4560
American Entomologist
Vol. 50, No.4, Winter 2004