Monterey BT Liquid Concentrate



A fast-acting microbial insecticide spray for controlling caterpillar infestations. This biopesticide works by introducing bacterial spores and toxins into the body of the insect larvae as it feeds on foliage. These toxins quickly disrupt, and soon completely stop, normal digestive functions of the pest insect. The infected larvae will cease eating within minutes and fully succumb to the effects of the BTK and die within 2-5 days.

Btk only affects the larval (caterpillar) stage of the the Lepidoptera order of insects. The Lepidoptera order includes gypsy moths, cabbage loopers, tomato hornworms and grape leaf skeletonizers. When used as directed it has no effect on birds, earthworms, or beneficial insects such as honeybees and ladybugs

  • Btk is not an effective control for corn earworm or squash vine borer.
  • Use only in a home garden setting.
  • Can be used on edible plants up to the day of harvest.
  • For best results, use at the beginning of the pest's life cycle (1st and 2nd instars)
  • Can be used on fruit and shade trees, vegetables, ornamentals and many other plants.
  • OMRI listed for use in organic gardening.
  • Active Ingredient: Bacillus thuringiensis subspecies kurstaki strain SA-12 
  • Controls worms & caterpillars on Fruits, Vegetables, Ornamentals and Shade Trees.


Bagworms, Cabbage loopers, Elm Spanworm, Fall Cankerworm, Fall Webworm, Spongy Moth, Imported Cabbage Worm, Spring Cankerworm, Tent caterpillars, Tomato Hornworm and more.