WSU Extension

Hortsense

Caption: Leafroller damage to fruit
Photo by: R.S. Byther
  
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Apple : Fruittree leafroller
(revision date: 2/14/2019)


Biology
The larvae of the fruittree leafroller feed on leaves, flower parts, and sometimes young fruit. They are pale to dark green with a shiny black head and are about 3/4" long at maturity. Typical symptoms of leafroller feeding include leaves that are rolled and tied in place with webbing and shallow surface damage on the fruit. The caterpillars are active when disturbed, wiggling vigorously or dropping to the ground on a thread. Larvae are usually mature by the end of May, and adults may be found any time from early June to mid-August. The adult moth is 1/2" to 3/4" long and mottled tan and brown. Other leafrollers may also be found on apple.
Management Options

Non-Chemical Management
  • Pick out and destroy rolled leaves and caterpillars, when practical.
  • Pinch rolled leaves to kill caterpillars.
  • Encourage natural enemies of caterpillars including birds, parasitic wasps and flies, and predacious beetles. Avoid use of broad-spectrum insecticides which kill beneficial insects.
Select non-chemical management options as your first choice!

Chemical Management


Bacillus thuringiensis will control leafrollers only when they are actively feeding. Use a spreader-sticker with liquid Bt formulations. Superior type oil used at the late delayed-dormant period helps control leafrollers. Apply spinosad once around the time of petal fall. 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.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • All Seasons Horticultural & Dormant Spray Oil Conc [Organic]
    Active ingredient: oil/pet distillate  |  EPA reg no: 4-80
  • Bonide Captain Jack's Deadbug Brew R-T-U [Organic]
    Active ingredient: spinosad (spinosyn A+D)  |  EPA reg no: 4-472
  • Bonide Thuricide BT Conc
    Active ingredient: Bacillus thuringiensis subsp. kurstaki  |  EPA reg no: 4-226
  • Bull's-Eye Bioinsecticide
    Active ingredient: spinosad (spinosyn A+D)  |  EPA reg no: 62719-314-56872
  • Monterey Garden Insect Spray [Organic]
    Active ingredient: spinosad (spinosyn A+D)  |  EPA reg no: 62719-314-54705
  • Naturalis L
    Active ingredient: Beauveria bassiana  |  EPA reg no: 53871-9
  • R-T-U Year-Round Spray Oil
    Active ingredient: oil/pet distillate  |  EPA reg no: 6218-78
  • Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
    Active ingredient: azadirachtin  |  EPA reg no: 70051-6-42697
  • This list may not include all products registered for this use.
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Caption: Leafroller damage to fruit
Photo by: R.S. Byther