Elm Zigzag Sawfly Scouting Guide

What is elm zigzag sawfly? Elm zigzag sawfly (EZS) is an invasive insect that feeds on elm leaves. Native to Asia, it was first detected in North America in 2020. Over the next five years, EZS was found in 14 states in the U.S., including North Carolina. EZS can strip mature elms of their leaves, causing stress and branch dieback. As a recent invader, the full impact of this insect in North Carolina is uncertain.

What to look for: 

• Zigzag feeding damage starting at the edge of the leaf and moving inwards
• Bright green larvae with black markings on the head and and legs
• Small (~ 1/4 inch), black adults with pale yellow legs and smoky black wings

When and where to look:

EZS is active from April to

September. To date, EZS has only been observed feeding on elms, but its entire host range is unknown.  To identify some of the native elems in NC, look for a leaf wit an asymmetrical base and doubly serrated edges.  During spring, elm trees produce a distinctive winged fruit, called a samara.  The fruit is round, with a papery ring surrounding the seed. Native elm trees have a rough bark with tall ridges.

What to do if you find EZS:

• If you find EZS or its damage:  report it to your NC Forest Service County Ranger or directly to researches at NC State using the QR code.
• If you have seen this distinct zigzag pattern ON ELM please contact Delaney Serpan so she can record your sighting: dlserpan@ncsu.edu.
• To find your NC Forest Service County Ranger go to https://www.ncagr.gov/divisions/nc-forest-service/contacts
• To protect your trees: find management recommendations at NC State Extension Forestry or contact me at minda_daughtry@ncsu.edu