Associate Certified Entomologist (ACE) Practice Exam

Which ingredient in pesticide formulations is responsible for supplying the mode of action?

1. Inactive ingredient

2. Active ingredient

3. Technical grade

4. Formulations

The correct answer is: Active ingredient

The active ingredient in pesticide formulations is responsible for supplying the mode of action. This component is the bioactive chemical that has a specific effect on pests, affecting their biological processes, physiology, or behaviors and ultimately leading to their control. It is this ingredient that determines the effectiveness and target specificity of the pesticide. In contrast, inactive ingredients serve primarily as carriers or enhancers that aid in the application, stability, or consistency of the formulation, but they do not have a direct role in controlling pests. Technical grade refers to the pure form of the active ingredient before it is formulated into a pesticide product, and formulations encompass the complete mixture of active and inactive ingredients. Therefore, while these other aspects are important for understanding a pesticide's performance and application, the mode of action is specifically attributed to the active ingredient.