Honey locust: Honeylocust pod gall midge

categories: Honey Locust Insects Ornamental trees Ornamentals

revision date: 2022-12-05 12:00

deformed, thickened, and pod-like in appearance of infected leaves compared to healthy leaves against a black background.
Honey locust pod gall midge
Photo by: R.S. Byther

Biology

The honey locust pod gall midge is a tiny orange gnat that lays its eggs on new foliage in the spring. The small pinkish or yellow-white maggots feed on the leaves, which become deformed, thickened, and pod-like in appearance. The larvae are sheltered inside the deformed leaves. Infested leaves may dry and drop from the tree. Small shoots may be killed. This is mainly an aesthetic concern, since the ornamental quality of the tree may be lost.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Pick and destroy infested leaves, when practical, to help improve appearance.
  • Prune out dead twigs and branches.
  • Black locust (Robinia pseudoacacia) is not attacked. The honey locust (Gleditsia triacanthos) variety ‘Shademaster’ is reported to be less susceptible, but ‘Sunburst’ is very susceptible.

Chemical Management

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

  • The key to successful management is protection of new foliage with a registered insecticide.
  • Sometimes repeat applications are needed, at 2-4 weeks, beginning late spring.
  • 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.