Pear sawfly
48 host plants
Last updated
You will see olive-green, slug-like larvae with a shiny coating feeding on hawthorn and mountain ash leaves in late spring and early summer. These caterpillar-like sawfly larvae skeletonize foliage by feeding on tissue between veins. Larvae appear in groups and curl their rear ends upward. Multiple generations overlap. Hawthorn and Sorbus species throughout Western Washington host this imported pest.
Remove infested leaves by hand when larvae are small and populations are localized. Prune heavily defoliated branches for appearance. Encourage parasitic wasps and natural enemies by avoiding broad-spectrum pesticides. Time applications for late May when second generation larvae are active. Most trees tolerate spring defoliation. Maintain tree vigor through proper care to enhance recovery.
Quick Reference
Cultural Controls
- biological control Specific biocontrol agents are not known, but this is rarely a pest in backyard gardens, so significant biocontrol likely occurs most years.
- Management-cultural control Home orchardists: Pick off individual larvae from infested leaves, or wash them off with a strong stream of water.
- Management-