Which microbial insecticide is commonly used to control caterpillars?

Bacillus thuringiensis, often abbreviated as Bt, is a microbial insecticide specifically known for its effectiveness in controlling caterpillars. This bacterium produces a toxin that is lethal to certain insect larvae, particularly those in the order Lepidoptera, which includes caterpillars that feed on various plants. When ingested, the bacteria's spores produce crystal proteins that disrupt the caterpillar's gut, ultimately leading to its death.

The relevance of this microbial insecticide lies in its targeted action, making it a popular choice for organic gardening and sustainable agriculture because it is safe for beneficial insects and does not harm other wildlife. This selectivity plays an essential role in integrated pest management strategies, where controlling pest populations while maintaining ecological balance is crucial.