The present book on Principles of Pesticides Chemistry is the outcome of difficulties encountered by the author while imparting knowledge of agricultural chemicals to their students. An attempt has been made to give an over view of all chemicals aspects of plant protection. The book presents a detailed characteristic of insecticides, fungicides, nematicides, fumigants, acaricides, herbicides, attractants, repellents and pheromones. Information is also given on Insecticides Act, biological control of pesticides, toxicology, formulation and residues aspect of pesticides.