Secret Weapons: Defenses of Insects, Spiders, Scorpions, and Other Many-Legged Creatures

Thomas Eisner, Maria Eisner, and Melody Seigler
Belknap Press (of Harvard University Press, Cambridge, MA)
2005; 372 pages, Price: $29.95
ISBN: 0-674-01882-6;

It is not necessary to travel to tropical rainforests or exotic islands to witness and enjoy the colorful beauty and amazing arsenals used during natural struggles among invertebrate species and their enemies. A mystical array of deadly toxins, biochemical explosions, inescapable sticky traps, deceptive coloration, and baffling behavior can readily be yours to view as you peruse this color-illustrated book on chemical warfare in arthropods. The book is a hybrid between an eco-tour guidebook of North American insects, spiders, centipedes, millipedes, scorpions, and spiders and a scientific treatise with extraordinary insights into the interface of chemistry, natural history, and biology. Each of the 69 minichapters contains close-up photos (mostly color), which carefully document offensive and defensive weapons (and ecological–evolutionary counter-maneuvers) in the miniature worlds of predator–prey interactions.

These three-to-five page stories of taxonomically diverse species will each hold readers’ attention in a way analogous to a great mystery novel or an action–thriller movie. Chapters include Arachnids (4), Chilopids & Diplopids (7), and many Insecta (including 9 Hemipterans, 3 lacewings, 22 beetles, 11 Lepidopterans, 3 Hymenopterans, etc.).

These great little natural history snippets entertain individually, but also hint at broader ecological patterns remaining to be discovered. The book is therefore motivational in the sense that we get an exciting peek at the intrigue and extensive natural diversity, without getting the impression that there is nothing left to learn. For example among the beetles, why does the chemical in some beetles repel jays, mice, carabid beetles, ants, and jumping spiders, but not mantids, assassin bugs, or centipedes? Why does blister beetle cantharidin not work against spiders, frogs, quail, or hedgehogs? Why is this chemical toxin attractive to other insects? What is the basic source of cantharidin in various insects, and why do males transmit it to females during copulation?

As with these beetle chapters, each chapter can be easily read, whether consecutively from the front to the back of the book, or individually in any order. The delightfully presented blend of chemistry, physiology, entomology, history, and evolution serves as a model for sensing the power of interdisciplinary research and the pleasure of witnessing the complexity and stunning precision of nature in action.

All entomologists will find this book delightful in its descriptions of various adaptive mechanisms used by invertebrates on the attack and in their defensive battles. This book will also be of interest to biology students of all ages, as well as college and high school teachers. The physically and chemically unique sprays, slimes, and sticky messes produced by centipedes, millipedes, spiders, scorpions, and insects will fascinate the reader. The book would also be excellent for gift shop visitors in insect zoos and butterfly houses worldwide. It would serve as a reference text for scientific guides and lecturers in an array of public science arenas, from garden clubs and invertebrate zoo exhibits to nature centers and educational camps or field trips.

Although the book emphasizes North American examples, it contains some international examples. The first chemical ecology class in the nation was presented in 1968 at Cornell University with Dr. Tom Eisner’s stories as a central theme. The examples extracted here (much as exciting minilectures) also reflect the vast array of behavioral, chemical, physical, acoustical, and visual aspects of invertebrate predator–prey interactions, which was the theme of Dr. Eisner’s Introductory Neurobiology and Behavior course.  His lectures were given with such enthusiasm that student applause inevitably followed every presentation. This collection of photos and natural history stories presents interesting details of various adaptations (numerous physical deterrents–defenses or offenses and the names and structural formulas of 149 distinctive chemicals are depicted, also illustrating some chemicals shared by taxonomically diverged arthropod groups).

From multiple defenses of the lubber grasshopper (repellents, hissing froth exudates, phenols, large leg spines, and visual distinctiveness) to the subtleties of lacewings that use skatole secretions (the smell of human feces) or the detachable bristles of a millipede that entangles and incapacitates predatory ants, this book is chock full of compelling examples of the little creatures that rule the world with their numbers and their uniquely bizarre adaptations. Caterpillars are described that spit (spray) formic acid, bungee-jump off leaves, mimic bird droppings, produce deterrent osmeterial secretions and toxic cyanide, and possess toxic urticating hairs that can even kill humans. Adult arctiid moths have alkaloid-laden wing scales that protect them (and their eggs) from web spiders. The widely distributed and well-recognized swallowtail butterflies of the world are included for the visual, behavioral, and chemical antipredator defenses in larvae and adults.

Perhaps the only disappointing aspect of this wonderful book is that it is page-constrained and can only provide short (but not superficial) glimpses of deeply fascinating chemical and physical warfare systems of arthropods. This information deficit is especially true for the ants and the bees. Also, the specialized and highly tuned evolutionary adaptations and co-adaptations in relation to plant chemistry (often resulting in multiple defense types and divergent life history “strategies” along multiple trophic levels) for myriads of insect-plant interactions are only alluded to briefly in this book. For readers interested in finding out more about the intricacies of the equally diverse, fascinating, and very closely related field of insect–plant interactions, I would refer to Insect-Plant Biology from Physiology to Evolution (Schoonhoven et al. 1998). In spite of the page limitations, each chapter in Eisner et al.’s book has 3–15 scientific references designed to get one quickly into the primary literature.

Reference Cited

Schoonhoven, L. M.  T. Jermey, and J. A. van Loon. 1998. Insect–plant biology from physiology to evolution. Chapman & Hall, London.

J. Mark Scriber
Dept. of Entomology
Michigan State University
East Lansing, MI 48824
American Entomology
Vol. 53, No. 2, Summer 2007