Tree wrapped with duct tape and tanglefoot. The gypsy moth caterpillars will climb up this tree, but won't go past the sticky tanglefoot. They will accumulate around the bottom of the duct tape. You can pick them off and destroy them. Don't smear the tanglefoot directly on the tree. The tanglefoot can damage the tree. Wrap the duct tape around the tree, and smear the tanglefoot on the duct tape.