But the incidence of outbreaks has never been brought under control. American interest in Taiwan's casuarina moth situation shows how concerned they are by this pest. To prevent the moth entering the US as a "stowaway" on ships from Taichung Harbor, for the last four years the US Department of Agriculture has sent personnel to Taiwan to act as observers and to assist in exterminating casuarina moths.
美國的憂心可從他們關心台灣黑角舞蛾的情形看出來，由於擔心黑角舞蛾可能隨著台中港船隻「偷渡」，步舞毒蛾之後「攻佔」美國，美國農業部已連續四年派人來台灣觀察、並協助撲殺黑角舞蛾。