Adults: The adult Elm Sawflies feed on the sap of trees by cutting into the bark of twigs. Many trees can become heavily infested and the trees can often become defoliated because of constant feeding.





Larva: The larvae primarily feed on leaves during the summer in order to obtain nutrients. The technique that is used by the larvae consists of them coiling up their posterior end around the leaf or twig so they can maintain a substantial grip while feeding. Also while feeding on leaves, the larvae use their pairs of legs, posterior to their head, in order to hold them in place.  The trees that the adult and larvae feed on consist of Elm, Willow, Maple, Cottonwood, and Poplar. An interesting technique that the Elm Sawfly larvae do while feeding on leaves is that they make zigzag patterns throughout the center of the leaf and do not consume the leaf's veins (U.S. Department of Agriculture 1974).