Chapter 4 Role of insect growth regulators in insect/pest control

Insecticides with growth regulating properties may adversely affect insects by controlling or suppressing specific biochemical pathways or processes necessary for their growth and development. Insect growth regulators (IGRs) are either synthetic chemicals or derived from other natural sources such as plants. These include chitin synthesis inhibitors, juvenile hormone analogs, anti-juvenile hormone, and molting hormone analogs. Insects exposed to such chemicals may die due to abnormal hormonal regulation, prolonged exposure at the developmental stage, or from an abnormal termination of a developmental stage itself. The main advantage of accepting IGRs is that they target juvenile harmful insect populations while causing less detrimental toxic effects to beneficial insects. In addition, some insects show resistance to synthetic insecticides, while they are less likely to become resistant against IGRs. On account of these advantages, the chemical composition of naturally occurring insect hormones is now being researched and used as a basis for the synthesis of analogs or mimics that are harmful to insects. The purpose of this publication is to explain the mechanism involved in the action of different classes of IGRs, their impact, and advantages in insect/pest control.