The larvae feed gregariously on new and old needles as well as the tender bark of young twigs. They generally feed downward from the top of the tree. After complete defoliation, they may crawl over ground for several yards to find new foliage. The Virginia pine sawfly primarily attacks Virginia pine but will feed upon short leaf pine and loblolly. Attack by this insect produces the most damage when they produce severe defoliation over several years or under drought conditions.
Young larvae are light green with a black head.
This sawfly spends the winter in the egg stage. The newly hatched larvae feed in groups on the previous year's growth, just below the tip. They ultimately eat all of the needle except the basal portion within the sheath. There is one generation each year with the larvae completing development in mid-May. The loblolly pine sawfly, a long time pest in Arkansas, has attacked loblolly pines in western Kentucky during some years.