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Juvenile sawfly larvae can appear in several different forms, depending on the variety. Often, they will look like small slug or worm. They feed on the soft tissue of leaves and on evergreens, consumeing the new needles. In a few cases, the sawfly larvae act as leafminers, living and eating within the leaf, never emerging outside of the leaf. The leafminer version is more difficult to control than the exposed juveniles, because being inside the leaf protects them.
At the first sign of the sawfly, spray the tree or plant with Borer-Miner Killer and repeat the spray every seven days until the infestation is controlled. When spraying is not possible, or when the juvenile sawfly is a leafminer, apply Once-A-Year Insecticidal Drench w/Merit.