A variety of different caterpillars spin silky, tent-like nests on trees. Depending on your location, local caterpillars may feed primarily on pine trees or flowering fruit trees. Nest-building caterpillars feed on tree leaves or needles early in the spring season, causing severe aesthetic damage. If defoliation persists over three years or more, the caterpillar damage can weaken the tree. Burning caterpillar nests, though a popular method of control, can damage tree limbs or start a fire. Though home gardeners cannot kill the nests per se, they can remove the nests with safe mechanical methods and exterminate any caterpillars inside.
Look for egg masses on tree twigs in fall, winter and early in spring.These masses look like brown or gray foam in a circle around a twig.
Scrape the eggs off with a butter knife into a bucket filled with soapy water.
Remove the silky, tent-like nests with your hands as soon as you notice them on trees.Wear work gloves, as certain types of caterpillars deliver a painful sting.
Drop the nest pieces and caterpillars into a bucket of soapy water to exterminate them.
Dispose of the dead caterpillars in the garbage or compost to prevent caterpillar odors in your home or yard.