Bacillus thuringiensis (BT) is used to control which pests?

• A. Beetles
• B. Caterpillars
• C. Grasshoppers
• D. Ants

Answer: (B)

Bacillus thuringiensis is used because its crystal toxins must be eaten by certain insect larvae, and caterpillars are the classic targets. When a caterpillar ingests the Bt spores and toxins, the toxins are activated in the acidic gut, bind to receptors in the midgut, and disrupt the gut lining, causing the insect to stop feeding and die. This mode of action makes Bt particularly effective against Lepidoptera larvae such as cabbage loopers, hornworms, and armyworms feeding on crops and ornamentals. Beetles, grasshoppers, and ants aren’t typically controlled by the common Bt formulations, so Bt is best described as a targeted option for caterpillar pests. It’s favored in many organic and integrated pest management programs because it acts on the pest larvae with limited non-target effects when used as directed.