There may be a combination of normal berries and galls on the same fruit cluster.

Initially the gall is green in colour but changes to red as it develops.

Larval feeding continues until late July, when the larvae drops out of the gall to the ground to pupate.

The hollow, damaged fruit will often drop off before the berries are ripe.

This article related to members of the fly infraorder Bibionomorpha is a stub.