The Toxicology And Biochemistry Of Insecticides

Despite their potentially adverse effects on nontarget species and the environment, insecticides remain a necessity in crop protection as well as in the reduction of insect-borne diseases. The Toxicology and Biochemistry of Insecticides provides essential insecticide knowledge required for the effective management of insect pests. Continuing as the

Insecticides: Action and Metabolism provides a comprehensive review of the action of insecticides and a survey of their metabolism. This book discusses the toxicology of insecticides. Organized into 17 chapters, this book begins with an overview of the mechanisms whereby toxicants exert their effects. This text then discusses the insecticidal action of organophosphates, which is described as the toxic organic compounds containing phosphorus. Other chapters consider the mode of action of organophosphates by inhibiting cholinesterase with consequent disruption of nervous activity caused by accumulation of acetylcholine at nerve endings. This book discusses as well the erratic patterns of selective toxicity to insects of the carbamates. The final chapter deals with the real hazard to human health as well as the effects upon wild life of insecticides and chlorinated pesticides. This book is a valuable resource for organic and agricultural chemists, as well as biologists, agriculturists, neurophysiologists, environmental scientists, and research workers.

Pesticide Chemistry: Human Welfare and the Environment, Volume 3: Mode of Action, Metabolism and Toxicology covers the proceeding of the Fifth International Congress of Pesticide Chemistry. This book is organized into three parts that tackle relevant issues regarding the use of pesticide. The opening part tackles topics relevant to the biochemistry of pests and mode of action of pesticides, such as influence of chlorinated and parathyroid insecticide on cellular calcium regulatory mechanisms; behavioral and lethal actions of amidines on invertebrates; and insect chitin synthetase as biochemical probe for insecticidal compounds. The second part encompasses metabolism and degradation of pesticides and xenobiotics and includes topics on propesticides; selective toxicity conferred by activation; and comparative biochemistry of animal, plant, and microorganism oxidases. The last part covers the toxicology of pesticides and xenobiotics, including the role of biochemical studies in modern toxicological assessment of pesticides; neurophysiological and behavioral assessment of pesticide toxicity; and genetic toxicology applied to the assessment of mutagenic, carcinogenic, and teratogenic action of pesticides and related compounds. This book will be of great interest to chemists, biologists, botanists, and entomologists or professionals whose line of work involves the use of pesticides and who are concerned with pesticide side-effects to the users and the environment.

Insects are more similar in structure and physiology to mammals than plants or fungi. Consequently, insecticides are often of greater toxicity to mammals than herbicides. This is particularly the case with neurotoxins. However, some insecticides are targeted at structures or hormonal systems specific to insects (insect growth regulators/chitin synthesis inhibitors) so are less harmful but can still be mildly haematotoxic. There are, therefore, issues specific to insecticides, which do not occur with other pesticides - hence the need for a book specifically on insecticide toxicology in mammals. The book starts with general issues relating to the mammalian toxicity of insecticides, including target/non-target specificity, nomenclature and metabolism of insecticides. It then goes on to discuss specific types of insecticides including: organochlorines; anticholinesterases; pyrethrum and synthetic pyrethroids; nicotine and the neonicotinoids; insect growth regulators/ecdysone agonists/chitin synthesis inhibitors; insecticides of natural origin; biological insecticides; and insecticides used in veterinary medicine.

Only four short decades ago, the control of insect pests by means of chemicals was in its early infancy. The pioneers in the area consisted largely of a group of dedicated applied entomologists working to the best of their abilities with a very limited arsenal of chemicals that included inorganics (arsenicals, fluorides, etc.), some botanicals (nicotine), and a few synthetic organics (dinitro-o-cresol, organothiocyanates). Much of the early research was devoted to solving practical problems associated with the formulation and application of the few existing materials, and although the discovery of new types of insecticidal chemicals was undoubtedly a pipe dream in the minds of some, little or no basic research effort was expended in this direction. The discovery of the insecticidal properties of DDT by Paul Miiller in 1939 has to be viewed as the event which marked the birth of modern insecticide chemistry and which has served as the cornerstone for its subse quent developement. DDT clearly demonstrated for the first time the dramatic potential of synthetic organic chemicals for insect control and provided the initial stimulus which has caused insecticide chemistry to become a field not only of immense agricultural and public health importance but also one that has had remarkable and unforseeable repercussions in broad areas of the physical, biological, and social sciences. Indeed, there can be few other synthetic chemicals which will be judged in history to have had such a broad and telling impact on mankind as has DDT.

The most rewarding aspect of writing a book is receiving encouraging comments from one's colleagues, since one always wonders whether fair coverage was made of the work of others or whether some omissions were made. I feel very fortunate that many colleagues took the time to read the first edition of this book and chose to use it as a textbook in their teaching. During the past few years they have given me valuable suggestions by pointing out areas that needed to be added to improve the book. Toxicology is one of the fastest moving scientific fields. In the areas of insecticide toxicology many new advances have been made since this treatise first appeared. Therefore, it would not be easy to write even a review paper that would not be outdated by the time it was published. In revising this volume I have made a conscious effort to adhere to the basic principles which have been developed over the years. While I have retained the basic framework of the original book, advances that fundamentally change certain concepts or add a new horizon have been chosen for updating those fields where applicable. The main emphasis has been placed on the addition of new sections and new compounds developed since 1975. Since the first edition appeared, several books covering technical details in each group have been published. They are excellent encyclopedic resources in their chosen areas, and are listed in each section as recommended reading material.