Associate Certified Entomologist (ACE) Practice Exam

What type of chemicals are combined with pyrethrins to enhance their effectiveness?

1. Acidic compounds

2. Alkaline substances

3. Synergists

4. Inhibitors

The correct answer is: Synergists

Pyrethrins, which are natural insecticides derived from chrysanthemum flowers, can be combined with synergists to enhance their effectiveness. Synergists are substances that, when added to another chemical, increase its potency without affecting its inherent properties. For example, piperonyl butoxide is a commonly used synergist with pyrethrins. It works by inhibiting the enzymes that some pests use to break down and detoxify the insecticide, allowing pyrethrins to work more effectively and providing a quicker knockdown of the target insects. The other types of compounds listed do not serve the same purpose as synergists. Acidic compounds and alkaline substances may influence the stability or activity of various chemicals but do not specifically enhance the effectiveness of pyrethrins in the same way that synergists do. Inhibitors, while they may alter processes, do not act to increase the efficacy of insecticides like synergists do. This makes synergists the correct choice for enhancing the effectiveness of pyrethrins.