Next, as the beefwood trees which were planted in large numbers during the Japanese occupation began to grow old, they also became hosts for the casuarina moth. Some people even suspect that the casuarina moth was introduced from outside Taiwan, and this is why it is able to do such damage to beefwood plantations.
接著，日據時期開始大量種植的木麻黃，垂垂老矣，也成為黑角舞蛾的宿主；更有人懷疑黑角舞蛾是由外地被引進台灣的「外來種」，才會對防風林造成強大殺傷力。