Gilbert Waldbauer
Harvard University Press, Cambridge, MA
2001, 264 pp.
Price: $16.95, paper
ISBN: 0-674-00686-0

The natural history of mostly nonsocial aggregations of insects is the focus of this interesting and charming book by entomological Professor Emeritus Gilbert Waldbauer. He uses a vibrant variety of collective nouns, with entertaining alliteration, to describe the fascination with which we view the apparent organization, or otherwise, of groups of insects.

The book is well organized to consider defensive aggregations (3 chapters), aggregations in response to weather (2 chapters), group behaviors associated with foraging and movement (4 chapters), mating (3 chapters), and associations with other species (a concluding chapter).

I found the book compelling and captivating. Waldbauer captures the delights of communing with nature so beautifully that time and time again, I was reminded of why I became an insect ecologist. We often forget these natural delights, and if you are feeling a little jaded from too many dull tasks, this book is a great way to rekindle your enthusiasm for nature and find that spark of excitement once again.

My one and only slight gripe is that I can’t understand why anyone still uses Imperial measures in science—inches, acres, and °F make me wince. The book may be aimed at a U.S. audience, but it’s about time that audience joined the rest of the world! If Harry Potter can be Americanized, perhaps Millions of Monarchs will also be available in metric.

I thoroughly enjoyed the seamless segues from natural history observation through functional explanation to background history, context, and then theme development. All sorts of gems of information enliven the discussion from accurate biologies, historical anecdotes, and insightful interpretations of phenomena for which we often have quite limited understanding.

Personally, I lament the loss of an entomological literature that values eloquence, ideas, and philosophy rather than brevity and frequency, and so I greatly enjoyed Waldbauer’s insightful discussions based on thorough understanding and excellent research of each phenomenon described. These discussions are all the more interesting because Waldbauer includes his own interpretations of many of the latest and best developments along the same themes. For example, the chapter on monarch butterflies is an eloquent and up-to-date summary of monarch biology with an emphasis on migration and overwintering aggregations and the role that chemical defense plays in the life history of monarchs. To me, this a great example of a beautifully written summary of a large and diverse literature that ranges from the dynamics of spatial and temporal distributions to the influence of abiotic conditions on hormonal physiology, to resource use, parent-offspring conflict, and defense against natural enemies, as well as to mate selection and the conservation biology and politics of Mexican overwintering forests. This is a tall order for a single chapter. But the order is met with accomplished charm and all sorts of relevant links to other chapters in the book.

A book of this nature is bound to be interesting to a wide audience when the author makes links between natural history and the environments in which we live and work. Thus, I enjoyed reading about the five-way link among telephone companies, eastern tent caterpillars, robins, cherry trees, and cuckoos: The robins eat cherries, perch on telephone wires, and liberate cherry seeds lubricated with laxative. Black cherries accumulate and are attacked by eastern tent caterpillars in their silken tents and, in turn, these caterpillars are a favored food of cuckoos.

This linkage formed the introduction to an interesting account of tent caterpillar research and the benefits of aggregations within or near their silk tents. Similarly, various interesting accounts of the biology of pest outbreaks are scattered throughout the book. It was a revelation to discover that locust swarms are not only of biblical significance, but have also been preserved in glacier ice,: or that in 1889, a fellow named Carruthers enthusiastically overestimated the massed weight of a locust swarm flying over the Red Sea at 24 trillion individuals that weighed 42.5 billion tons. Luckily, Waldbauer corrects the hyperbolic mathematics for us and gives revised values of 40 billion locusts that weighed 125,000 tons for the same swarm. But in anyone’s book, this is a lot of insects and illustrates forcefully how important insect aggregations can be.

The overenthusiastic locust count was a trivial fate for a paper published in the journal Nature, in comparison with the excommunication by an ecclesiastical court of a plague of locusts in the Austrian Tyrol in 1338. In a fascinating chapter, Waldbauer describes many such historical accounts of insect pest outbreaks, ranging from Pliny’s loony insect pest remedies to the salvation of katydid-ravaged Mormon crops by California gulls in Utah, and he includes insects such as flies, weevils, caterpillars, and grasshoppers.

Although the emphasis is on aggregations of nonsocial insects, the author gives inevitable glimpses of social bees, wasps, ants, and termites because these are the aggregators par excellence, by virtue of their Hamiltonian evolutionary gene dynamics. Waldbauer even includes interesting descriptions of other animal aggregations, such as the synchrony in time of red knot migration to exploit the eggs of spawning horseshoe crabs on the Atlantic coast of the United States. But the overwhelming target of the book is insects and the many, many ways in which they aggregate for food, sex, defense, and survival in variable climates.

The emphasis on nonsocial insects prompts Waldbauer to ask the question, why do so few predatory arthropods prey cooperatively, when many vertebrates benefit from foraging aggregations and are able to suppress costs of cannibalism? No answer is given, but I think the question highlights the value of his survey of biological aggregations. The question also helps to illustrate the descriptions of herbivorous insects that do feed in groups and benefit from aggregation and why they differ.

The only surprise for me was that aphids are only mentioned in passing. Cicadas have their own chapter, but aphids are relegated to the status of coccinellid food or targets of ant mutualisms and don’t receive the attention that their phloem-sucking aggregations probably warrant. Nevertheless, this delightful book is full of enthusiasm and information and well worth reading.

Stephen B. Malcolm
Department of Biological Sciences
Western Michigan University, Kalamazoo, MI 49008
American Entomologist
Vol. 50, No.1, Spring 2004