National Audubon Society Field Guide to North American Insects and Spiders (National Audubon Society Field Guides)
There are about 100,000 kinds of insects in North America, so obviously they can't have a field guide in the same way the 650 species of birds do: something both portable and complete. The National Audubon Society has produced a remarkably useful compromise. This guide has photographs and descriptions of 550 insect species and 60 kinds of spiders. Most of the families of arthropods on the continent are covered, as are all of the most common species. It's a very useful resource for any North American naturalist, and the best choice for an adult who is not an expert entomologist.--Mary Ellen Curtin