Which of the following is an example of biological control?

• A. Predators (ex: lady bugs)
• B. Atrazine
• C. Bacillus thuringiensis
• D. Cyfluthrin

Answer: (C)

Biological control uses living organisms or their products to reduce pest populations. Bacillus thuringiensis fits this idea because it’s a living bacterium used as a microbial biopesticide. When applied, Bt produces specific toxins that infect and kill certain insect larvae after they ingest them, helping manage pest populations with high target specificity. It’s commonly used in the field and is valued for its ability to control pests while being less disruptive to many beneficial insects and the environment when used as directed.

Predators like lady bugs are also a form of biological control, since they reduce pests through natural predation, but this item highlights a microbial biopesticide. Atrazine is a chemical herbicide, not a biological control, and cyfluthrin is a chemical insecticide.