CAHNRS > Hortsense > Fact Sheets > Ornamentals > Ornamental trees > Crabapple > Crabapple Insects > Crabapple: Leafrollers and leaftiers

Crabapple: Leafrollers and leaftiers

categories: Crabapple Crabapple Insects Ornamental trees Ornamentals

revision date: 2024-04-08 11:46

Leaf roller damage on rhododendron leaves.
Rhododendron leafroller leaf damage
Photo by: Unknown

Biology

Several species of caterpillars will roll and tie leaves of fruit trees. Characteristic signs of feeding include leaves that are webbed, rolled, and tied, often with frass in the webbing. Damaged leaves often turn brown and may drop prematurely. The larvae often group together to make nest-like structures of chewed leaves and webbing. Leafrolling and leaftying caterpillars are usually about 1-2″ long at maturity.

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-pick and destroy individual caterpillars when practical.
  • Pinch to kill caterpillars inside rolled leaves.
  • Prune out and destroy nests of caterpillars.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • Pesticide recommendations are for flowering (non-edible) crabapples.
  • Apply in early spring, but not during bloom.
  • Use a spreader-sticker with liquid Bt formulations.
  • 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.

  • All Seasons Horticultural and Dormant Spray Oil Concentrate [Organic]
    Active ingredient: mineral oil/pet distillate [EPA registration number: 4-80]
  • Monterey Garden Insect Spray [Organic]
    Active ingredient: spinosad (spinosyn A+D) [EPA registration number: 62719-314-54705]
  • R-T-U Year-Round Spray Oil
    Active ingredient: oil/pet distillate [EPA registration number: 6218-78]
  • Safer Brand BioNEEM Multi-Purpose Insecticide and Repellent Concentrate [Organic]
    Active ingredient: azadirachtin [EPA registration number: 70051-6-42697]
  • Garden Safe BT Worm and Caterpillar Killer
    Active ingredient: Bacillus thuringiensis subsp. kurstaki [EPA registration number: 9688-294-39609]
  • This list may not include all products registered for this use.

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