Associate Certified Entomologist (ACE) Practice Exam

Which of the following is NOT an example of a macrocyclic lactone?

1. Abamectin

2. Ivermectin

3. Chlorantraniliprole

4. Emamectin

The correct answer is: Chlorantraniliprole

Macrocyclic lactones are a class of drugs that are primarily used in veterinary and human medicine for the treatment of parasitic infections. These compounds work by interfering with the nervous system of susceptible parasites, leading to paralysis and death. Abamectin, Ivermectin, and Emamectin are all well-known macrocyclic lactones derived from the fermentation of soil-dwelling bacteria. They are effective against a wide range of internal and external parasites and are widely used in both agricultural and veterinary settings. Chlorantraniliprole, on the other hand, belongs to a different class of insecticides known as anthranilic diamides. It works by activating ryanodine receptors in insects, leading to muscle paralysis and ultimately insect death. This mode of action is distinctly different from that of macrocyclic lactones, which primarily function by modulating the neurotransmission in parasites. Therefore, identifying Chlorantraniliprole as not belonging in the macrocyclic lactone category is accurate due to its unique chemical structure and mode of action compared to the other three substances listed.