Dipel Dust contains B.T. (Bacillus Thuringiensis), a biological insecticide control for Tomato Hornworm, Looper, Webworm, Armyworm, Cutworm, Leaf Roller, and other caterpillars on vegetables, fruits, ornamentals, flowers, and lawns. Dipel dust works as a stomach poison. After biting a treated portion of the leaf, caterpillars stop feeding within a few hours. Death then follows in a few days. Apply when caterpillars first appear or the sight of their damage. Complete coverage at 7 to 10 days intervals due to insect egg hatch. May be applied up to time of harvest.