David Pimentel, an American entomologist best known for his study of the energy and environmental consequences of different agricultural systems. His book Food, Energy and Society (1979) was the first to describe the fundamental role that energy plays in food production, the dependence of industrial agriculture on fossil fuels, and the need for the sound management of soil, water, energy, and biological resources in the entire food system. Pimentel made important contributions to the understanding of the ecological effects of pesticides on natural ecosystems and human health. These findings were made in his effort to improve pesticide effectiveness while reducing the hazards of these agricultural chemicals.