The third edition of Insect Ecology: An Ecosystem Approach provides a modern perspective of insect ecology that integrates two approaches traditionally used to study insect ecology: evolutionary and ecosystem. This integration substantially broadens the scope of insect ecology and contributes to prediction and resolution of the effects of current environmental changes, as these affect and are affected by insects. The third edition includes an updated and expanded synthesis of feedback and interactions between insects and their environment. This updated material and a new chapter on applications of insect ecology to social and environmental issues effectively demonstrates how evolutionary and ecosystem approaches complement each other, with the intent of stimulating further integration of these approaches in experiments that address insect roles in ecosystems. Effective management of ecosystem resources depends on evaluation of the complex, often complementary, effects of insects on ecosystem conditions, as well as insect responses to changing conditions.