Douglas Fir: Douglas fir needle midge

Biology

The tiny white larvae of the Douglas fir needle midge mine the inside of needles, which become yellowed and distorted. Infested needles often have a sharp bend at the injury site. Three different midges infest Douglas fir: one species feeds near the needle base, one feeds near the tip of the needle, and the third feeds near the middle. Damaged needles often drop from the tree, and heavy midge infestations can cause severe defoliation. The midges pupate in the ground, with the adults emerging around bud-break in the spring. The adult Douglas fir needle midge is a small fly. This can be a serious pest in Christmas tree plantations.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

• Where practical, prune out heavily infested twigs.
• Use emergence traps on the ground to catch adults. This will help determine the need for control. Contact your county Extension agent for further information.

Chemical Management

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

• Control must be applied during budbreak.
• 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.