Adult moths
The adult moths that gather around lights on summer evenings are not gardeners' enemies, because they seldom feed on plants. It's the moth larvae that chew on, bore into, and roll themselves up in plants’ leaves, fruits, stems or roots. The larvae, which are called caterpillars or worms, represent the main feeding stage in a moth's life cycle. Caterpillars eat heartily to store energy for their development in the cocoon and eventual metamorphosis into winged adults.
Not all moths are harmful
Many moth species cause little damage and should be left alone. Also keep in mind that some caterpillars turn into beautiful, harmless butterflies.
The worst pests
The worst pests are gypsy moths, webworms, leaf miners, budworms, and bagworms. Watch for codling moths, cankerworms, and leaf rollers on fruit. Cutworms, borers, tomato hornworms, and cabbage loopers prefer vegetables. You can control moths as eggs, larvae, or adults.
Pheromone traps
Pheromone traps, which lure adults with sexy scent, work in two ways. They capture moths in a sticky substance and alert you to when the pests are active. You can then time spraying to kill eggs or larvae. Just hang traps from trees that are likely to be infested.
Good bacteria
Bacillus thuringiensis (Bt) is not only effective against gypsy moth larvae, but bagworms, cabbage loopers, codling moths, and tent caterpillars as well.
Control larvae of codling moths
Control larvae of codling moths, gypsy moths, and others by using barriers that trap caterpillars as they crawl down trees. Tie a six-inch strip of burlap around a trunk tightly with twine. Check under the fabric regularly and destroy any pests you find.
Eliminate moths
To control many moth larvae, pick them off plants and squash them, or drop them in a pail of soapy water.
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Adult moths are usually not garden pests, but their larvae can wreak havoc on a garden.
