A New Invasive Zigzagging Across North America

Elm zigzag sawfly damage

There’s a new invasive insect zigzagging its way across North America. First reported by citizen scientists in Quebec in 2020, the elm zigzag sawfly (Aproceros leucopoda) has now spread to North Carolina, Virginia, Maryland, Ohio, Pennsylvania, New York, Massachusetts, and Vermont. This new pest, which is native to Asia, has the potential to cause major devastation to one of our native tree species.

Invasive Insect Elm Zigzag Sawfly Confirmed in Vermont

Elm zigzag sawfly damage

The invasive insect known as Elm zigzag sawfly (EZS) has been confirmed for the first time in Vermont. After receiving a report of potential EZS activity in northwestern Vermont, staff from both the Forest Health program of the Department of Forests, Parks, and Recreation (FPR) and Plant Health program of the Agency of Agriculture, Food, and Markets (AAFM), collected larval samples from affected elm foliage in May 2023.  Samples were sent to the US Department of Agriculture Plant Protection and Quarantine program for identification, and EZS has now been officially confirmed within the state.

May Freeze Damage

Frost damage

Public reports and staff observations recorded damages across the state from Highgate to Halifax, with cold pockets and river valleys seeing the most extensive damage. Most reports of freeze damage in forests stated damage to members of the Fagaceae family, including American beech (Fagus grandifolia) and red oak (Quercus rubra) regardless of geographic location.

May Freeze Damage

Vermont Woodlands Association is partnering with the Vermont Department of Forests, Parks and Recreation to gather more information about the geographic extent of the damage as well as the species involved.