Hazelnut gall midge

Systematic position: The hazelnut gall midge (Contarinia coryli) belongs to the order Diptera and the family Cecidomyiidae. It is an important pest that specializes in hazelnuts, often remaining undetected until significant damage to the crop has already occurred.

Host plants: The primary host for this insect is the cultivated hazelnut (Corylus avellana). Its activity can cause severe reduction in yield, as the larvae feed directly on the nut kernels, making the product unmarketable.

Biology and life cycle: The insect typically completes one generation per year. Adult midges emerge in spring, coinciding with the flowering period of hazel trees. Females deposit eggs into the developing nuts. The emerging larvae feed inside the kernel, and once fully developed, they drop to the soil to overwinter in cocoons until the next season.

Damage and economic impact: The damage is primarily caused by larvae feeding on the endosperm of the nut. Infested hazelnuts often exhibit premature yellowing, deformation, or shriveling. In many cases, the entire fruit drops prematurely, leading to substantial yield losses in commercial hazelnut orchards.

• Regular monitoring of the orchard to detect early signs of adult activity.
• Sanitary measures, including the collection and destruction of infested nuts and fallen fruit.
• Cultivation of the soil beneath the canopy to disturb overwintering pupae.
• Application of selective insecticides during the egg-laying period, when permitted.
• Deployment of pheromone or sticky traps to monitor population density and timing of intervention.