The larvae tunnel in the shoots of purple willow (Salix purpurea).

The larvae live in separate chambers under the bark of shoots of purple willow (Salix purpurea).

Before the larvae pupate they make emergence holes which, along with some discolouration of the bark on top of the shoot, may be the only indication of their presence.

[1] Redfern et al. (2011) no longer consider R. justini to be a gall causer.

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