Phytocoptella avellanae, Cecidyopsis vermiformis (Big bud mites)
They are very small mites . It is really hard to see the mites by bare eyes. White,small, 0.2 mm long, with numerous tergites and sternites. Before foliage or after defoliage, big buds become more visible in hazelnut orchards.
Biology and Damage
This pest is very common in Turkish and Georgian hazelnut orchards. They attacks the cellular walls of the internal parts of the current year’s bud shoots, which, as early as September, begin to become larger and deformed. In spring , the females leave the deformed buds to invade the young leaves and lay eggs. The nymphs develop freely and change into adults in June-July before invading the new buds of the current year’s shoots. The adults breed in autumn and winter. This pest causes important reductions in the harvest. The attacked buds begin to become deformed as early as September, they enlarge and external scales widen considerably. The buds destined to give female flowers seem to be preferentially invaded.
Mechanical control is very effective against big bud mites. Especially from October to early April big buds are easly seen in orchards and must be collected by hands. For chemical control, Sulphur is usually sprayed during mite migration from buds to leaves in April.