Associate Certified Entomologist (ACE) Practice Exam

What is the mechanism of action (MOA) for pyrroles?

1. Block nerve impulses

2. Inhibit energy production within the cells

3. Disrupt GABA-activated channels

4. Interfere with calcium channels

The correct answer is: Inhibit energy production within the cells

The correct answer, which states that pyrroles inhibit energy production within the cells, relates to how these compounds function biochemically to kill or control pests. Specifically, pyrroles act by disrupting the normal mitochondrial function in target organisms. Mitochondria are responsible for energy (ATP) production, and when their activity is inhibited, the energy required for cellular processes is compromised. This ultimately leads to the death of the pest because they cannot generate the necessary energy for survival. This mechanism highlights the unique role of pyrroles as an insecticide that targets energy metabolism, differentiating them from other classes of pesticides that may operate through different pathways. In contrast, other mechanisms of action listed in the options involve different targets. Blocking nerve impulses relates to neurotoxic insecticides that aim to disrupt nerve function, while disrupting GABA-activated channels would affect neurotransmission and might not be the primary action of pyrroles specifically. Interfering with calcium channels typically involves other insecticide classes that influence muscle contraction and signaling, which is not the mechanism associated with pyrroles. Thus, the focus on energy production makes the choice about pyrroles particularly relevant and accurate.