Sawflies also tend to roll into an ‘S’ shape when they are disturbed. Pest description and damage Mature birch sawfly larvae are yellowish with rows of black spots along the abdomen and 0.75 inch long. Western Forest Insects. The tree tolerates the feeding and does not seem to be suffering any adverse effects but I do not like what I think are their droppings (green/brown pellets the size of a pea with texture resembling a corn cob). Prune out leaf or area with larvae. There are two generations of dusky birch sawfly; spring and fall. Dusky birch sawflies will have two generations each summer and overwinter in the soil as pre-pupae. Bathe or shower after each use. Dusky birch sawflies will have two generations each summer and overwinter in the soil as pre-pupae. Copyright © 2020ISU Extension and Outreach The adults do not eat and cannot sting. Why. Some of the leaves in my river birch are turning yellow and dropping to the ground. Management: Look for dusky birch sawfly during spring and again in mid-summer. Edge effects like this aren’t unusual and can be caused by various factors. Sawfly larvae have prolegs on the abdomen but no crochets on the ends of the prolegs. They also feed on birch but usually cause only localized damage. Sawfly larvae typically feed in clusters. Want to see which lists are available? Dusky birch sawfly is a darker yellowish-green with 3 dark spots on each segment. Taylors, SC 29687, Charlotte Office: Symptoms: Dusky birch sawfly have two generations per year and can start out very small, almost too small to see. Damage is usually localized and rarely do they cause significant defoliation. Appearance. However, this is difficult to predict.Here is our publication on birch Upon closer examination I saw several groups of a dozen or so yellow-green bodies with black spots and black heads chomping away at the leaves. 231 Tanner Drive Action: The dusky birch sawfly’s primary host is River birch, but sometimes grey, black, red paper and yellow birch are also attacked. Cooperative Extension has offices in every county, Entomology – Insect Biology and Management, Current Western NC Orchard Insect Populations, Biological Control of Brown Marmorated Stink Bug, Spotted-Wing Drosophila Research and Extension Priorities, 2012, Spotted-Wing Drosophila Needs Assessment, 2011, Insect Management on Fruiting Vegetables in North Carolina, Insect Management on Cucurbit Vegetables in North Carolina, Benefits of Applying Insecticides With Drip Chemigation, Biological Control With Predators and Parasitoids, Biological Control of Spider Mites in Tomatoes, Managing insect pests in organically certified corn, Powderpost Beetles and Wood-Inhabiting Fungi, Pests of Conifers — Insect and Related Pests of Shrubs, Insect Management — North Carolina Soybean Production Guide, Minor Pests of Fraser Fir Christmas Trees, Organic Pest Control in Fraser Fir Christmas Trees, Mountain Horticultural Crops Research & Extension Center, Vernon G. James Research & Extension Center, Mountain Horticultural Crops Research and Extension Center, Weed Management in Nurseries, Landscapes & Christmas Trees. The same thing that connects it to every corner of North Carolina: NC State Extension. USDA Forest Service, Misc. Dusky birch sawfly is a darker yellowish-green with 3 dark spots on each segment. Other species eat holes in the leaves and then eventually entire leaves. Damage . (Optional) Don’t worry, though. Carolyn. Description: Sawfly larvae are often mistaken for caterpillars. How to Reduce Bee Poisoning from Pesticides, Alfalfa Leafcutting Bee (Megachile rotunda) Pests, Horticultural, Landscape, and Ornamental Crops, Field Characteristics of Fruit-Tree-Attacking Spider Mites in the Pacific Northwest, Pests of Cabbage and Mustard Grown for Seed, Pests of Rutabaga and Turnip Grown for Seed, Biology and Control of the Garden Symphylan, Bean, Dry Cultivar Resistance to Bean Common Mosaic, Grape (Vitis spp.) However, sawflies are different in their habits and how they must be controlled. There are two generations of dusky birch sawfly; spring and fall. Completely equipped truck for immediate production. Hosts. Right now they are in the larval stage of their second generation. The site may not look or function as expected. The dusky birch sawfly is an occasional pest of birch trees, particularly river birch. Learn how your comment data is processed. But it's the worm-like larva that causes damage to plants. Typically, sawflies are shinier than caterpillars. Products like Bacillus thuringiensis (Bt) will not work on them since they’re not caterpillars. Why? The adult is easily recognised by the pale band on its shiny black abdomen. 864.244.3088864.244.3088, Tryon Office: When I ventured off trail into the forest they were nowhere to be found. Imidacloprid (click for sources) is a systemic insecticide which can be applied to the soil around the tree before feeding activity is noticed. They do not have the constricted waist of many stinging wasps.