A well-maintained garden is one of the best defenses against damage from caterpillars-the larvae of butterflies and moths. Feed and water plants adequately. Cultivate and weed weekly. Be alert to drooping stems and partly eaten foliage and remove them. By avoiding pesticides, you’ll encourage the presence of caterpillar predators, such as birds, parasitic wasps, lady beetles, and praying mantises.
Promptly after harvesting, burn or trash old leaves and stems; caterpillars can overwinter in them. Dig or rototill your garden in the early spring to expose and destroy pupae. Leaf-eating caterpillars Wearing gloves, handpick large caterpillars and drop them into a pail of warm soapy water or water topped with 1/2 inch of kerosene. For major infestations, spray with Bacillus thuringiensis, a natural control toxic only to caterpillars.