These small flies are little known as adults but commonly encountered as larvae where they feed inside the flower capsules of Senecio - Ragwort. Both species in this aggregate are believed to feed on Ragwort in similar ways and it is currently unclear if they can be distinguished as larva. Adults can be separated by using an appropriate key.

Affected Ragwort flowers fail to develop fully and a tell-tale white frothy ball appears at the top of the capsule. This froth is produced by the larvae as it feeds. Developing larvae can completely fill the flower capsule.

as larvae on Ragwort

Senecio is the main larval foodplant.

July-August

Common.

Common.