River Birch Worm Control: Sawfly Identification and Treatment

Homeowner asks how to eliminate worms on river birch.

Pest: Birch Sawfly

Larvae feed in groups, can defoliate tree.

Small trees: Hand-pick and destroy caterpillars.
Large trees: Spray foliage with Orthene (acephate). Available at nurseries/garden centers.

Trees: River Birch Webbing: Spider Mites or Fall Webworms—Not Spiders; River Birch Surface Roots Near Building: Do Not Cut—Add Sand, Prune Limbs Instead; River Birch for Southern Exposure in Ohio: Wind-Resistant & Fast-Growing; New River Birch Trees Slow to Leaf Out: Water, Don't Fertilize; Ice‑Damaged River Birch: When to Remove a Broken Trunk; Birch Defoliation by Caterpillars: To Spray or Not?; River Birch Defoliated by Caterpillars: Identify, Spray Now, Prevent Next Year; Heritage River Birch Dropping Twigs: Twig Girdler; Why Is My River Birch Dripping Water from Its Branches?; Selecting the Right Tree for a Sloped Site Near a House in Wisconsin

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