Students and teachers in entomology and plant pathology departments have much experience of this. "Whenever we go out collecting specimens, we always see the tree-tops swarming with caterpillars," says Professor Yang Ping-shih of National Taiwan University's Department of Entomology.
植病、昆蟲系師生的經驗豐富，「每回出去採集，都會看到毛毛蟲爬滿樹梢」，台大昆蟲系教授楊平世說。