Nature's Way Caterpillar Killer - Dipel is an organically certified insecticide for control of a wide range of caterpillars. Safe to beneficial insects, birds and animals. Yates Nature’s Way Caterpillar Killer is based on Bacillus thuringiensis var. kurstaki, which is an insecticide derived from beneficial bacteria found in soil, on plant surfaces and also in insects. It specifically targets caterpillars and is safe for beneficial insects such as ladybirds and bees. Bacillus thuringiensis var. kurstaki affects the insect’s digestive system. The bacteria produce a toxic protein that paralyses the insect’s gut. Once a caterpillar eats treated foliage, it stops eating but may take up to 3-4 days to die and drop from the leaf. Yates Nature’s Way products are based on natural, low toxic & organic ingredients. To help protect and repair our environment, Yates donates a percentage of sales to Landcare.