Ornamental Pear: Pear slug (pear sawfly)
categories: Ornamental Pear Ornamental Pear Insects Ornamental trees Ornamentals
revision date: 2023-04-04 12:00
Photo by: R.D. Akre
Biology
The pear sawfly is also known as the pear slug (or ‘cherry slug’ when on cherry) because of its resemblance to a small, dark slug. These insects are the larval stage of a glossy, black sawfly about 1/5″ long. The larvae are covered with a dark green to black slime which gives them the slug-like appearance. The caterpillar-like larvae are yellow immediately after molting until the slime is produced. Larvae are also yellow-orange immediately before pupating. Pear slugs feed on upper leaf surfaces, skeletonizing leaves. Severe infestations can cause defoliation, weaken trees, and affect fruit development on fruiting varieties.
Management Options
Use Integrated Pest Management (IPM) for successful plant problem management.
Non-chemical Management
Select non-chemical management options as your first choice!
- Hand removal is effective on small trees.
- Natural enemies control pear slug populations fairly effectively. Avoid use of broad-spectrum insecticides which can kill beneficial insects.
- Wash pear slugs from trees with a strong stream of water.
Chemical Management
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.
- Chemical control measures are rarely necessary except for very severe infestations.
- Apply when larval damage approaches 25% to 30% defoliation.
- Homeowners should not make foliar applications to trees over 10 ft tall.
- Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.
Approved Pesticides
Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
Additional Images
Photo by: C. Berg
Photo by: C. Berg