Associate Certified Entomologist (ACE) Practice Exam

What is the primary effect of neonicotinoids on insects?

1. Stimulates the insects' digestive system

2. Inhibits energy production in the cell

3. Prevents transmission of information between nerve cells

4. Offers a high toxicity to mammals

The correct answer is: Prevents transmission of information between nerve cells

Neonicotinoids primarily act as agonists at nicotinic acetylcholine receptors in the nervous system of insects. By binding to these receptors, they disrupt the normal transmission of nerve impulses, leading to overstimulation of the nervous system. This excessive stimulation can ultimately result in paralysis and death of the insect. The mechanism of action is particularly selective for insects, making neonicotinoids effective as insecticides while generally having lower toxicity to mammals. This selectivity is key to their use in pest control, as it allows for targeting pest species without causing significant harm to non-target organisms, including humans. The other options do not accurately describe the primary effects of neonicotinoids: - The stimulation of the digestive system is not a known or primary effect of neonicotinoids. - Inhibiting energy production in the cell is not related to the action of neonicotinoids; rather, this effect might be more characteristic of other types of toxic agents. - While neonicotinoids are designed to be less toxic to mammals, they do not offer high toxicity to these animals, which highlights their specificity for insect pests rather than mammalian physiology. Thus, the choice that correctly identifies the primary effect of neonic