What is blackcurrant gall midge?
Blackcurrant gall midge is a tiny (up to 2mm long) yellowish-brown fly. Feeding by the flies larvae causes leaves to become distorted and crumpled.
The females lay eggs between the folds of newly emerged leaves. The eggs hatch a few days later and orange-white larvae feed on the leaf surfaces for 10 to 14 days before going into the soil to pupate. Their feeding prevents normal expansion of the leaves which remain small, distorted and crumpled. Damage to established bushes is usually not serious although the distorted foliage is unsightly and may be mistaken for the symptoms of reversion disease. Young blackcurrant bushes and cuttings can suffer a more serious check in growth.
There are three generations during the summer with adult flies laying eggs in late April to early June, late June to early July, and late July to August. It is however, the first generation of larvae that is often the most damaging. The third generation of larvae, that finish feeding in August, spend the winter as pupae in the soil.