Adult yellowheaded sawflies are stingless wasps, measuring at about 1/3 inches long. They are a defoliator of spruce trees throughout our region.
Detection & Treatment
The yellowheaded sawfly will, in time, strip spruce trees of their needles. Early detection includes the top needles of the tree turning a reddish-brown color. There are a handful of methods for treatment, including pruning the crowns of infested trees as well as chemical treatment.