Safer Brand 1 Gallon Caterpillar Killer Concentrate eliminates caterpillars and worms, including corn earworm, bollworm, diamondback moth, hornworms, loopers, melonworm, tomato fruitworm, tobacco budworm, salt marsh caterpillar and many more. This powerful b.t. formula provides you with enough product to treat row planting, making it ideal for commercial applications. Safer Brand Caterpillar Killer uses DiPel (bacillius thuringiensis var. Kurstaki) which, once ingested by the caterpillar or worm, kills them within a few days. This insect killer is the most economical and convenient natural pest control solution for caterpillars and worms on the market. It is recommended to apply in the afternoon or on cloudy days since b.t. breaks down rapidly in sunlight.