Which of the following is an example of a biological control agent used in crops?

• A. Chemical pesticide
• B. Lacewing
• C. Mechanical weed control
• D. Fertilizer

Answer: (B)

Biological control uses living organisms to reduce pest populations in crops. Lacewings are classic beneficial insects whose larvae hunt and eat many soft-bodied pests like aphids, whiteflies, and mites. Releasing or protecting lacewings in fields helps keep pest numbers down naturally, often as part of an integrated pest management strategy, and can reduce reliance on chemical pesticides.

In contrast, a chemical pesticide is a non-living substance used to kill pests, mechanical weed control is a physical method of removing weeds, and fertilizer is a nutrient source for crops. None of those are living organisms, so they’re not biological control agents.