Blackcurrant gall midge
Blackcurrant gall midge can cause the leaves of blackcurrants to become distorted and crumpled.
Latin name: Dasineura tetensi
Plants affected: Blackcurrant
Main symptoms: Small, distorted, crumpled leaves
Caused by: The larvae of a small midge
Timing: Spring and summer
What is blackcurrant gall midge?
Blackcurrant gall midge is a tiny (up to 2mm long) yellowish-brown fly. Feeding by the larvae of this fly causes leaves to become distorted and crumpled.
Gall midges are a family of flies, the Cecidomyidae, there are more than 600 species found in Britain. As adults most are small brown or black flies, they do not bite. As the name suggests many species feed as larvae within plant tissues causing galling and distortion. Some are however, predatory on aphids and mites whilst others feed on rust fungi.
Blackcurrant gall midge 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. On established bushes this is usually not serious although it may be mistaken for the symptoms of reversion disease. Young blackcurrant bushes and
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 apparent. The third generation of larvae, that finish feeding in August, spend the winter as pupae in the soil.
Check blackcurrants frequently from spring onwards so action can be taken before a damaging population has developed.
- Damage from this midge can often be tolerated as cropping or vigour in home gardens and allotments is rarely affected
- Hoeing the soil under bushes during dry weather in the summer may destroy some of the pupae by exposing them to drying conditions
- Affected leaves can be picked out, although this may cause more damage than the insect
- Some blackcurrant cultivars, such as ‘Ben Connan’ and ‘Ben Sarek’, are resistant to this midge. Removing affected shoots can help reduce infestation levels
- Pesticides should not be used against blackcurrant gall midge, none of those available are likely to have any effect on the mite and they will kill non target invertebrates, including predators of the midge
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.