Bacillus thuringiensis or Bt is a bacteria commonly used in the biological control of worms and caterpillars. Bt kills worms and caterpillar stage insects, but has no effect on birds, earthworms, or beneficial insects such as honeybees or ladybugs, when used as directed.

Worms and caterpillars eat treated foliage, then immediately stop feeding and damaging plants. Best results when sprayed when worms or caterpillars are small.

• Effective for controlling cabbage looper, armyworms, hornworms and other Lepidopteran (moth) pests feeding on vegetables.
• Also controls tent caterpillar, gypsy moth, bagworm and more on shade trees and ornamentals.
• Acceptable for use on edible plants up to the day of harvest.
• You may apply Monterey B.t. Concentrate up to and on the day of harvest.