What is the primary function of Insect Growth Regulators (IGRs)?

Insect Growth Regulators (IGRs) primarily serve to prevent immature insects from maturing into adults by interfering with the hormonal processes that govern their development. By mimicking or disrupting the hormones responsible for growth and development, IGRs effectively stunt the growth of the target pest's life cycle. This prevents them from reaching reproductive maturity, thereby reducing the population over time since they do not produce offspring. This method of control is particularly valuable because it targets the growth processes of pests without directly killing them, which can help in managing pest populations sustainably and minimizing impacts on beneficial insects.

The other options presented do not accurately reflect the primary function of IGRs. While some pest control methods aim for instant kill or enhanced reproduction, IGRs focus specifically on disrupting developmental stages rather than direct lethality or promoting reproduction.