This scientific monograph deals with coccinellids (ladybirds), a group of beetles which are beneficial predators of aphids, scale insects and mites, and are also one of the most popular insects. This volume is an updated and modified version of "Biology of Coccinellidae" (1973). While the information goes into enough detail for a researcher or university teacher, the book should also be easily readable for the naturalist who is interested in the background behind the observed phenomena. Extension agriculture specialists should find ths text a friendly guide to the use of coccinellids in integrated pest management and biological control.