Gleditsia gall midge

The Gleditsia gall midge (Dasineura gleditchiae) is a small dipteran insect belonging to the family Cecidomyiidae. It is a specialized pest that exclusively targets Gleditsia species, causing distinct deformities known as galls on the foliage.

The primary host plant for this insect is the honey locust (Gleditsia triacanthos). It is particularly problematic in nurseries, landscapes, and urban forestry settings where host density allows for rapid population expansion and severe infestations.

The life cycle of the gall midge is synchronized with the bud burst of the host tree. The insects overwinter as pupae in the soil beneath the canopy. Upon the arrival of spring, adults emerge to mate and lay eggs within the developing leaflets. Depending on climate and weather conditions, several generations can occur within a single growing season.

Damage is characterized by the formation of pod-like galls. Each gall is formed by the curling and thickening of leaf tissues around the developing larvae. Affected leaves fail to expand properly, become discolored, and eventually drop prematurely. This process impacts the tree's photosynthetic capacity, stunts growth, and detracts significantly from the plant's aesthetic value.

Effective management strategies include:

• Applying systemic insecticides when the first leaflets appear to target adult midges and larvae.
• Practicing good sanitation by raking and removing infested foliage to break the life cycle.
• Cultivating the soil around the base of the trees to disturb or destroy overwintering pupae.
• Maintaining vigorous tree health through appropriate irrigation and nutrient management to withstand infestations.