National Audubon Society Field Guide to Insects & Spiders
Here's what other sites are saying:
Spiders, bugs, moths, butterflies, beetles, bees, flies, dragonflies, grasshoppers, and many other insects are detailed in more than 700 full-color photographs visually arranged by shape and color. Descriptive text includes measurements, diagnostic details, and information on habitat, range, feeding habits, sounds or songs, flight period, web construction, life cycle, behaviors, folklore, and environmental impact. An illustrated key to the insect orders and detailed drawings of the parts of insects, spiders, and butterflies supplement this extensive coverage.