As with many plant-feeding insects, the dogwood sawfly is one of those pests that rarely draws much attention but occasionally can be very destructive. A report of damage early this week provides a good opportunity to review this interesting and variable group.
Individual sawflies have normal appetites for insects their size; it is the group feeding that can cause problems. Sawfly eggs are laid in loose clusters in leaf tissue. Early feeding damage caused by the small caterpillar-like insects is easy to overlook. However, leaf consumption increases dramatically as they grow, so defoliation can occur almost overnight. In addition to the enhanced impact of group feeding, the appearance of these larvae changes as they develop (Figure 1). It can appear that more than one pest species is active.
Since dogwood sawfly larvae tend to occur in groups, it is often convenient to remove and destroy a few leaves to end the infestation. There is only one generation each year.
By Lee Townsend, Extension Entomologist