Associate Certified Entomologist (ACE) Practice Exam

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

1. Target adult insects directly

2. Promote rapid growth in insects

3. Hinder the development of immature insects

4. Eliminate eggs from the environment

The correct answer is: Hinder the development of immature insects

The primary action of Insect Growth Regulators (IGRs) is to hinder the development of immature insects. IGRs are compounds that interfere with the normal growth and development processes in insects, particularly during their juvenile stages, also known as larval stages. They act by mimicking hormones that regulate growth, thereby disrupting the molting process and preventing immature insects from developing into adults. This inhibition can lead to various outcomes, including reduced fertility of adult insects, population control, and, ultimately, a decrease in pest populations. By focusing on the life stages prior to adulthood, IGRs effectively reduce the number of mature insects that can reproduce, making them a valuable tool in pest management strategies. They are especially useful in controlling pest populations without directly killing adult insects, which helps to minimize the impact on non-target species and beneficial insects that may be present in the environment.