Associate Certified Entomologist (ACE) Practice Exam

Which compound is NOT an example of a Chitin Synthesis Inhibitor?

1. Hexaflumuron

2. Lufenuron

3. Methoprene

4. Diflubenzuron

The correct answer is: Methoprene

The correct choice identifies Methoprene as a compound that is not a chitin synthesis inhibitor. Methoprene is classified as a juvenile hormone analog. It functions by mimicking the action of juvenile hormones in insects, which are crucial for regulating development and growth, especially during the larval stages. This mechanism affects an insect's ability to transition from one life stage to another but does not inhibit the synthesis of chitin itself. In contrast, other compounds like Hexaflumuron, Lufenuron, and Diflubenzuron specifically inhibit the synthesis of chitin, which is an essential component of the exoskeleton in insects. Chitin synthesis inhibitors interfere with the proper formation and hardening of this structural polysaccharide, leading to abnormal growth and ultimately the death of the insect. This distinction between the actions of chitin synthesis inhibitors and juvenile hormone analogs is key to understanding their differing roles in pest management strategies.