Associate Certified Entomologist (ACE) Practice Exam

Which feature is common to both spinosyns and neonicotinoids in their action against pests?

1. Both affect calcium channels

2. Both target acetylcholine receptors

3. Both are categorized as synthetic compounds

4. Both require ingestion for effectiveness

The correct answer is: Both target acetylcholine receptors

The action of spinosyns and neonicotinoids against pests is characterized by their ability to target acetylcholine receptors. Neonicotinoids are synthetic analogs of nicotine that bind to nicotinic acetylcholine receptors in the nervous system of insects, causing a disruption in their normal function, ultimately leading to paralysis and death. Similarly, spinosyns, which are derived from the fermentation product of the actinomycete Saccharopolyspora spinosa, also interact with acetylcholine receptors, although they do so in a somewhat different manner. They bind to specific sites on the insect's nicotinic receptors, enhancing synaptic transmission and resulting in hyper-excitation of the nervous system. This shared mechanism of action—modulating the activity of acetylcholine receptors—highlights a crucial similarity between these two classes of insecticides, making this feature significant in their effectiveness against pest populations. Understanding this interaction is essential for pest management strategies since it underscores how both groups can impact neural functioning in target insects. The other options do not correctly characterize a common feature shared by both spinosyns and neonicotinoids. For instance, while both are synthetic compounds, focusing solely on their synthetic nature does not account