The holly leafminer feeds on English (Ilex aquifolium), American (I. opaca) and Japanese (I. crenata) hollies, tiny green blisters on the lower leaf surface often indicate sites where the females deposited eggs. Characteristic damage by larvae includes the presence of yellow, brown, or reddish mines on the leaves. Initially the mines are fairly narrow and winding, but become large blotches as the larvae overwinters in the leaf. The upper and lower leaf surfaces remain after feeding, but are easily separated. Larvae are yellowish and about 1/16" long. The adult is a small black fly.

Management Options

Non-Chemical Management

Hand-pick and destroy infested leaves in the fall.
Pinch leaves to kill leafminers inside mines.
Natural predators may help control populations. Encourage predators such as green lacewings and spiders.

Select non-chemical management options as your first choice!

Chemical Management

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

If you choose to use a pesticide, apply just before bloom. 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.

Bayer Advanced Power Force Multi-Insect Killer R-T-S
Active ingredient: cyfluthrin | EPA reg no: 72155-39
This list may not include all products registered for this use.

Images

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Caption: Holly leafminer Photo by: R.S. Byther
Caption: Holly leafminer Photo by: A.L. Antonelli

WSU Extension

Hortsense