After gypsy moth (Lymantria dispar) caterpillars get about an inch long in mid-June, they will move down the trunk to hide from predators during the day. You can take advantage of this behavior to trap and reduce the number of larvae on the trees in your yard by making a burlap barrier band trap. To make a band, cut a strip of burlap 12-18 inches wide and long enough to reach around the tree and overlap a few inches. Tie a string around the center of the band and allow the top six inches to flop over to make a two-layered skirt. Tie the band around the tree above the sticky band (if you have one in place). Check the bands every day from early afternoon until about 6 p.m. Lymantria dispar caterpillars have hairs that can irritate the skin, so use rubber gloves or forceps to collect all caterpillars from the burlap band. Place the collected caterpillars in a container of soapy water to kill them. If you find any adults or pupae on your trees, you can also kill them by placing them in the container of soapy water. Once the insects are dead, drain off the water and throw the insects in the trash. Take the burlap bands down in August.