Currant shoot gall midge

Resseliella vespicoloris, known as the currant shoot gall midge, belongs to the order Diptera and the family Cecidomyiidae. It is a highly specialized pest that significantly impacts the health and productivity of currant plantations worldwide.

This insect primarily attacks black and red currant species. The pest focuses its destructive activity on young shoots, utilizing the inner bark and cambium layers as a food source for its larvae, which disrupts the normal growth of the plant.

The biological cycle of the midge involves overwintering as larvae in cocoons within the soil under the bushes. Adult flies emerge during the flowering period of the host plant. Females lay their eggs in bark fissures on young branches, where the hatched larvae begin feeding under the epidermis.

The damage manifests as discolored, necrotic spots on the shoots. As the larvae feed, the bark becomes sunken, brittle, and eventually cracks. This leads to the wilting and death of the upper portions of the shoots, causing severe yield loss and potentially the destruction of the entire plant if infestation is heavy.

Effective protection strategies include:

• Pruning and burning affected shoots during the dormant season.
• Mulching the soil around bushes to block adult flies from emerging.
• Targeted chemical application during the emergence of adult midges.
• Maintaining plant vigor through balanced fertilization to help bushes recover from injuries.