The elm zigzag sawfly (Aproceros leucopoda, SLF) is one of the latest non-native species to take hold in the U.S. It was first found in Virginia in 2021, and active infestations are now established in Maryland, New York, North Carolina, and Pennsylvania. EZS has not been detected in South Carolina, but it is an insect for which we need to be on the lookout.
EZS has 2 generations per year in North Carolina and will likely have at least that many in South Carolina when and if it arrives here. EZS overwinter as pupae and adults emerge in spring to mate and lay eggs. Larvae (Fig. 1) feed exclusively on elm (Ulmus spp.) leaves, first creating distinct wavy feeding patterns before consuming nearly all the foliage on a leaf (Fig. 2). Adults resemble small, black flies. In North Carolina, larvae are present right now!
EZS feeds on elm trees, including our native slippery elm, winged elm, and American elm, as well as English elm, Siberian elm, Chinese elm, and hybrids. EZS will feed on elms in both natural and managed areas. To be clear, we have NOT documented this pest in South Carolina yet, but we are asking everyone to please be on the lookout for this elm-eating pest.
More information on the elm zigzag sawfly can be found on this Clemson Extension fact sheet: https://hgic.clemson.edu/factsheet/elm-zigzag-sawfly/. If you think you have found an elm zigzag sawfly, please contact the Clemson Department of Plant Industry at invasives@clemson.edu or by calling 864-646-2140.
Figure 1. Elm zigzag sawfly larvae are small, green, and have black markings on their head and legs.
Photo by Matt Bertone, NC State University.
Figure 2. Elm zigzag sawfly damage. Young larvae make characteristic zigzag feeding patterns that start at the edge of a leaf (A) while older larvae consume all but leaf veins (B). Larvae can cause large amounts of defoliation (C).
Photos by Kelly Oten, NC State University.
