The elm zigzag sawfly (EZS), Aproceros leucopoda Takeuchi, was detected in the United States for the first time in Virginia in 2021. In 2022, it was confirmed in 4 additional states: Pennsylvania, North Carolina, Maryland, and New York. These are the first records of this species in the United States and demonstrate a rapid range expansion of an invasive defoliating pest. Native to Asia, EZS feeds exclusively on Ulmus spp. (elms; Ulmaceae). In the United States, feeding damage ranges in severity from minor to severe. Young instars create a zigzag-shaped pattern in leaves as they feed, while older larvae feed more completely on foliage, leaving only the midvein and sometimes thick lateral veins. This more complete feeding often obscures the signature zigzag defoliation of younger instars. Long-term health impacts to host trees are unknown, though aesthetic damage, growth loss, and branch dieback occur in Europe where it is also invasive. Little is known about management options for this pest, and continued expansion of this species’ range in the United States is expected.

中文翻译：

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美国首次记录榆树之字形锯蝇（膜翅目：Argidae）

榆树之字形锯蝇 (EZS) Aproceros leucopoda Takeuchi 于 2021 年在美国弗吉尼亚州首次发现。2022 年，又在另外 4 个州得到证实：宾夕法尼亚州、北卡罗来纳州、马里兰州和纽约州。这是美国对该物种的首次记录，表明这种入侵性落叶害虫的范围正在迅速扩大。EZS 原产于亚洲，仅以榆属植物为食。（榆树；榆科）。在美国，喂养损害的严重程度从轻微到严重不等。幼虫在进食时会在叶子上形成锯齿形图案，而年长的幼虫则更完全地以叶子为食，只留下中脉，有时还有粗的侧脉。这种更完整的喂养常常掩盖了年轻龄虫标志性的锯齿形落叶。对寄主树木的长期健康影响尚不清楚，尽管美观受损、生长丧失和枝条顶枯发生在欧洲，但它也是侵入性的。人们对这种害虫的管理方案知之甚少，预计该物种在美国的范围将继续扩大。