Boxwood: Boxwood leafminer

categories: Boxwood Boxwood Insects Ornamentals Shrubs

revision date: 2023-04-04 12:00

Boxwood leafminer damage.
Boxwood leafminer
Photo by: A.L. Antonelli


Leafminers feed by removing green tissue from between the upper and lower leaf surfaces. Feeding by leafminers can be detected by the presence of yellow to brownish blotch-like mines or by a blistered, thickened appearance of the leaves. The larval stage of the boxwood leafminer is a small yellow to green maggot found inside the mined leaves. The adult is a small (1/10″) orange to yellow fly which emerges in early May. Damage is mainly aesthetic, but repeated severe infestations may damage shrubs.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Plant varieties of English boxwood (Buxus sempervirens) such as ‘Suffruticosa’, ‘Pendula’, and ‘Argenteo-varigata’, which are reported to be seldom damaged.
  • Pinch to kill maggots in infested leaves when practical.
  • Pick and destroy infested leaves when practical.
  • Provide proper culture to maintain plant health. Healthy plants are more tolerant of insect damage.
  • Natural predators may help control populations. Encourage predators such as green lacewings and spiders.

Chemical Management

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

  • If you choose to use a pesticide, apply when leaves are fully formed (around May 1st).
  • Make a second application between mid-June and mid-July.

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.