Abstract
This handbook comprises seven chapters that deal specifically, as far as possible, with various aspects of insect toxins. Chapter 1 introduces the subject with an emphasis on definitions and the role of toxins as a whole. Avoidance of allelochemicals on the basis of their toxicity is an outcome of interactions at various physiological levels, and chapter 2 discusses the concepts and mechanisms involved in the process. In relation to the response of insects to these chemicals, evaluation is important, and so various bioassay procedures have been developed. These are discussed in chapter 3 and are both generalist as well as species specific. A critical examination of functional groups present in the active molecules provides crucial information about the optimal relative stereochemistry required to induce the toxic action in insects. This is the main aim of chapter 4, where sufficient structure-activity information is generalized within specific skeletal systems to allow rational modification of readily available toxic compounds into potential insect control agents. Whether such toxins are specific to insect pests or if they have any impact on natural enemies is also important in developing any insecticidal product. Thus, chapter 5 deals with the impact of such compounds on natural enemies that could help in the development of a potential commercial product. Are any such commercial products available and, if so, how far have they made an impact in the conventional chemical insecticide-dominated market? This important aspect is dealt with comprehensively in chapter 6. The last chapter, chapter 7, is based on the bioefficacy of plant materials and is divided into two sections: Section A, which considers the bioefficacy of isolated compounds; and Section B, which covers the bioefficacy of extracts, oils and mixtures.