by By Charley Eiseman and Noah Charney
Stackpole Books, 2010
There are some 90,000 species of insects in North America, far more than any other group of organisms (compare this to the approximately 700 bird species found in the same geographic area). Several field guides have been published that offer a reference for people wanting to learn to identify these six-legged critters, but no books that I’m aware of have focused so extensively on the signs of insect presence, which is virtually everywhere you look. In Tracks & Sign of Insects and Other Invertebrates, Charley Eiseman and Noah Charney offer a firstever look at many phenomena associated with insects, helping to identify the creators and explain what’s going on.
More of an information or reference guide than a field guide, this book examines the multitude of evidence that insects leave all around us. The book is laid out in paragraph format rather than the plates typically found in field guides. This allows the authors to go into detail beyond a simple captioned photograph. The book is stuffed with full-color images, many taken by the authors during a 15,000 mile, 40-day road trip they undertook for the purpose, but quite a few of the photos were collected from other amateur and professional entomologists.
The text is information-rich, easy to read, and logically organized. The various categories of insect sign fall into broad chapter headings such as “Eggs and Egg Cases,” “Leaf Mines,” “Galls,” and “Sign on Twigs, Stems and Stemlike Structures.” Eighteen chapters treat everything from dragonfly exuviae (the shed exoskeleton left behind after the moult from nymph to adult) to the scrapings left by a snail’s “teeth” as it forages, to the folded-over leaves many caterpillars and other insects use for shelter, to the various burrows some insects make in the sand. You’ve probably seen many of the signs in this book but didn’t realize that they were made by insects; after flipping through the guide, you’ll go back to have another look.
If there’s one tiny disappointment I have with the book, it’s that they don’t have a better treatment of the different bark beetle gallery patterns encountered on dead logs and trees, among the most easily-observed of insect sign during the winter months. Still, the complaint is a small one, and their coverage of other topics is excellent. Thirty-three pages are dedicated to the many different types of spider web, thirty-two cover a variety of leaf mines, twenty-seven discuss the galls found on leaves and twigs; there are even thirty-seven pages on the tracks insects leave in sand and mud as they travel. Common phenomena are well-represented, but other observations are also given admirable treatment, and I have been able to identify many findings simply from flipping through the book.
I highly recommend this guide to anyone who, like me, has a tendency to pause and puzzle over curious things they encounter while out hiking. Eiseman and Charney have done an outstanding job compiling what is undeniably an overwhelming amount of diverse information. This book will be taking a spot on my bookshelf as one of my primary go-to insect guides.