Elm zigzag sawfly

Elm zigzag sawfly (EZS), Aproceros leucopoda, is an invasive insect pest from East Asia that exclusively feeds on elms (Ulmus). While first detected in North America (Quebec, Canada) in 2020, EZS has since been reported in numerous states in the northeastern and mid-Atlantic areas of the U.S. Small EZS populations are generally not a significant concern, however populations can build throughout a growing season and large populations can rapidly defoliate and harm an otherwise healthy elm.