Yang Ping-shih says that if large trees on school campuses are pruned regularly, the likelihood of caterpillar swarms is reduced, and if lymantriid moths do appear there is no need for spraying--all that is necessary is to keep people away from the trees for the time being.
楊平世說，校園裡的大樹，只要平日多加修剪，就可以減少毛毛蟲大發生，遇上毒蛾，也不需刻意消毒，只需暫時與之隔離。