Invasive species that can significantly damage elm trees found in North Carolina

North Carolina's latest invasive species has been found in western North Carolina, the state Department of Agriculture and Consumer Services said.

The elm zigzag sawfly was found just north of Pilot Mountain in the Westfield community. The elm zigzag fly can cause significant damage to elm trees because of their ability to quickly increase population size, forest health specialists said. Female zigzag sawflies can reproduce without mating, which means the insect can have multiple generations per year.

The insect, which is native to Asia, had only previously been found in Québec, Canada in 2020 and Virginia in 2021.

Anyone who thinks they see an elm tree being impacted by the elm zigzag sawfly is asked to note the location, try to safely photograph the insect and leaves that have been eaten and contact the local North Carolina Forest Service county ranger.

While typical defoliation from an insect doesn't result in long-term health impacts to a tree, forest health specialists said it's too early to know if that's the case with the elm zigzag sawfly.

Elm zigzag sawflies are considered harmless to humans. They are named for the saw-like appendage used for egg laying, and as young larvae, they leave a zigzag pattern in leaves while eating.

As adults, the insects are strong flyers that can hitchhike on soil or as cocoons attached to different objects, experts said.