Sawfly
Symphyta
16 host plants
Last updated
Yellow-green sawfly larvae with black spots and black head capsules feed on birch leaves, with early instars consuming interveinal tissue and late instars consuming entire leaves. When disturbed, larvae form their bodies into an S-shape. Dusky birch sawfly larvae can reach up to 1 inch length and feed in groups around leaf margins.
Distinguish sawflies from caterpillars: sawflies have 6 or more abdominal prolegs. Monitor May through July for feeding. Heavy infestations cause defoliation, but established trees tolerate damage. Prune infested branches if desired. Chemical control rarely needed on healthy birches.
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Two types of sawfly are pestiferous in caneberry crops and cause two distinct types of damage. Onycholyda sitkensis larvae roll leaves and feed within the rolled leaves, which is inconsequential; the main concern is that they can be a contaminant in harvested fruit especially in mechanically harvested fields. Monophadnoides rubi larvae do not roll leaves but feed on leaves, leaving holes on leaf edges or between the leaf veins. Extensive feeding by Monophanoides larvae may skeletonize the...