The brownheaded ash sawfly is commonly found in the eastern United States and southern Canada.
A heavy infestation can cause complete defoliation of the tree in a week, but there is only one generation of larvae each year and new leaves soon grow.
[6] They pupate in the cocoon in early spring,[2] emerging as adult insects when the ash leaves begin to unfurl.
[2] Two red-eyed vireo were witnessed bashing the larvae against a twig up to eighteen times, and then consuming them with multiple swallows without any noise.
[7] Other birds observed consuming the larvae in the study were a rose-breasted grosbeak, an English sparrow, and two catbirds.