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Caption: Spruce needleminer larva
Photo by: R. Van Denburgh
  
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Spruce : Spruce needleminer
(revision date: 4/20/2015)


Biology
The spruce needle miner feeds on spruce needles from the inside out, starting at the base of the needle. These larvae are light greenish to brown and grow to approximately 1/2" long. Large amounts of webbing are deposited around the needles. Completely mined needles may be cut off, sometimes resulting in severe needle loss. The spruce needleminer attacks mainly blue, Sitka, and Engelmann spruce in the western U.S. The adult is a small brown moth.
Management Options

Non-Chemical Management
  • Natural predators may help control needleminer populations.
  • Hand-pick larvae on small trees.
  • Plant resistant species.
Select non-chemical management options as your first choice!

Chemical Management


Apply late May or early June when moths and young larvae appear. Horticultural oils, soap-based products and some other products may cause discoloration of spruce needles, particularly on Colorado blue spruce. Read labels carefully and test on a small area before application. 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.
  • Bonide Systemic Insect Control
    Active ingredient: acephate  |  EPA reg no: 239-2461-4
  • This list may not include all products registered for this use.
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Caption: Spruce needleminer larva
Photo by: R. Van Denburgh