Webworms can be a serious pest of many species of shade, fruit and ornamental trees. Trees may be heavily or completely defoliated. This can cause branches and tops of the trees to die. The fall webworm moth will emerge in the spring and lay eggs. Later in the summer the eggs will hatch and the new worms will immediately begin to spin webbing over the foliage they are feeding on. As they grow they will expand the webbing. As they mature they will leave the web. There can be up to 4 generations of webworms a year.
Generally natural predators will keep the webworms under control. If there are large populations they may need our help. A non-chemical control is to prune off any developing webs. If this is not practical an insecticide may be used. Several are labeled for webworm control. Follow the label directions for application rates. Contact your county Extension office or Master Gardener hotline for more information.