自从舞毒蛾在1869年传入梅德福地区以来,已对美国东北部的森林造成灾害.近年来已蔓延至纽约、新泽西岛和宾夕法尼亚州等地,每年使500万公顷的林木受害落叶.舞毒蛾虽经控制,但效果不大,继续向美国南部与西部扩展.因此,人们对此表示忧虑. The gypsy moth has caused disasters in the forests of the northeast United States since it was introduced to the Medford in 1869. In recent years it has spread to New York, New Jersey and Pennsylvania, killing five million hectares of trees every year. Although the control of the moth is not effective, it continues to expand to the south and west of the United States, so people are worried about it.