When caterpillars invade your vegetable garden, you will need a solution--fast. Caterpillars can do a lot of damage in a small amount of time. Signs of a caterpillar invasion include chewed leaves and misshapen fruits. Non-toxic, effective controls are available to reduce or eliminate the destruction caused by these common garden pests.
Begin with a physical attack. Early morning or late evening are the prime caterpillar hunting times. Look on the underside of leaves, flicking off anything that looks like an egg cluster, and pick off any adult caterpillars. Drop them into an empty cup and release them several hundred yards away from your vegetable garden. You can also drop them into soapy water to kill them.
Spray with an earth-friendly bacterial. Bacillus thuringiensis (Bt) is favored by many gardeners because it is selective; it is safe for many beneficial insects as well as fish, birds and mammals. It is mixed with water.
Release the parasites. Trichogramma wasps are small parasites that feed on the eggs of moths and caterpillars. When you purchase Trichogramma wasps, they will arrive inside parasitized moth eggs. Hang the eggs in your garden and wait for them to hatch. There are several species of Trichogramma; T. pretiosum is used on vegetable and field crops.
Practice good garden hygiene. Remove dead leaves and debris at the end of the season and prune and dispose of any diseased plants. Disinfect tools regularly.