Residual pesticides are described as:

• A. No residual activity
• B. Remain active and control pests for days, weeks, months, and in some cases even years
• C. Applied to leaves
• D. Inert

Answer: (B)

Residual pesticides are pesticides that keep working after they’re applied, providing ongoing control against pests. Their activity persists for extended periods—days, weeks, months, and in some cases even years—depending on the chemical’s stability, formulation, how it’s applied, and environmental conditions. This lingering effect is what sets residual pesticides apart from products that act only at the moment of contact. The idea that a pesticide is simply applied to leaves describes the method of use, not its persistence, and the term inert refers to non-active ingredients, not the lasting activity of the product. So the key concept is that residual pesticides remain active long after application, offering continued pest control.