Attract Beneficial Insects to the Yard
Spiders and other predator insects will kill many more tomato hornworms than a homeowner armed with insecticide ever will. If you don't use broad-spectrum insecticides, you should have lots of beneficial insects such as green lacewings, braconid parasitic wasps, and paper wasps. All are great hornworm eaters.
Wasp House Trick: Paper wasps hunt caterpillars to provide food for their young. They will nest in your yard if you provide adequate shelter. Build some small boxes, about 6 inches square, and leave them open at the bottom. Paint them brown or black and fasten them to stakes placed in sunny areas. The wasps will build nests inside the boxes.
Encourage the natural predators of tomato hornworms to stay in your yard by providing them with a tempting variety of their favorite plant sources of pollen and nectar. One product, Border Patrol™, is a seed mix of wildflowers particularly attractive to beneficial insects, and includes evening primrose (Primula), wild buckwheat (Eriogonum), candytuft (Iberis), baby blue-eyes (Nemophila Menziesii), bishops flower , black-eyed Susan (Rudbeckia hirta), strawflowers , nasturtiums (Tropaeolium), angelica, and yarrow (Achillea). Click here for more information about Attracting Beneficial Insects.
Feed Birds Year Round
Next to beneficial insects, songbirds consume the most pest insects in your yard. Even seed-eating birds such as sparrows and finches hunt for insects to feed their young. A single pair of sparrows that live in your yard may have 3 broods of 3 to 4 young a season. The parents must collect vast numbers of insects in your yard to feed them.
Tomato hornworms are a favorite food for almost all birds, including Baltimore orioles, bluebirds, flycatchers, barn swallows, downy woodpeckers, sparrows, blackbirds, grackles, and phoebes. So the more birds you attract to your yard as residents, the fewer hornworms you will have to worry about. (Moles, skunks, and toads eat their share as well.) To enlist the birds’ help in your fight against pest insects, provide food, water, and shelter for bird families. Click here for more information about Attracting Birds To Your Landscape .