Pine Sawfly
Sawfly adults are non-stinging wasps. It is the larvae that damage your landscape plants and cause concern. All pines are susceptible to sawfly damage, but Scots and mugo pines are the most susceptible.
Life Cycle
Sawfly adults lay eggs inside pine needles late in the season. These eggs hatch when the weather warms and the larvae emerge and begin feeding. They then pupate for most of the summer and emerge as adults in late summer.
Damage
Sawfly larvae feed in tight groups and rear up when disturbed. They often go unnoticed for about the first three weeks of their development due to their small size and unobvious feeding damage. It is once they gain some size and their appetites increase that people take notice.
Sizeable larvae consume entire needles before moving on to the next one to do the same thing. They feed on all needles except the current season’s needle growth. This can be damaging to plant health, even fatal for mugo pines.
Control
Sawfly larvae are easy to control and damage can be avoided with careful monitoring. Small populations can be removed by hand or knocked to the ground with water from a garden hose. They typically do not find their way back up the plant and become subject to predators.
Large populations can effectively be controlled by use of an insecticide.
Please contact your RYANPro for assistance controlling this landscape pest