PETERSON FIRST GUIDES: Trees by George...

PETERSON FIRST GUIDES: Trees by George A. Petrides, illustrated by Olivia Petrides & Janet Wehr and Caterpillars by Amy Barlett Wright (Houghton Mifflin: $4.95 each; 128 pp., illustrated, paperback originals). The attractive “First” guides show amateur naturalists how to recognize characteristics that will enable them to make positive identifications. These elements range from the patterns of spines on a caterpillar to the way the leaves branch from a twig. Bizarre details, including the “false faces” the larva of the tiger swallowtail uses to frighten enemies, make the volume on caterpillars seem more interesting, although the discussions of how Amerindians used the products of various trees provide diverting reading. Either book would enrich a summer picnic or hike.