Which of the following is an example of a mechanical control?

• A. A pheromone lure for disruption
• B. A biological release
• C. A chemical attractant bait
• D. A trap or barrier

Answer: (D)

Mechanical control uses physical methods to prevent or remove pests, relying on blocking access, trapping, or physically removing them rather than using chemicals or living organisms. A trap or barrier fits this idea because it directly stops pests or captures them with a physical device or structure. Nets, row covers, screens, and other barriers physically exclude pests from reaching the plants. The other options involve chemicals or biological agents—pheromone disruption uses chemical signals to alter pest behavior, a biological release adds natural enemies, and a chemical attractant bait lures pests to a kill or trap. These are not mechanical methods.