A red or pink, kidney-bean-shaped gall, found on the leaves of Salix species (willow) and caused by the small sawfly, Pontania proxima (family, Tenthredinidae). A second brood laid in the early autumn by the adults that emerged in summer may over-winter in the gall. Sometimes the term ‘bean gall’ is used more generally to describe any red or brown gall caused by any Pontania species. Many galls may occur on a single leaf and, like other gall-causing species, the insects support a large community of parasites and hyperparasites.
Subjects: Plant Sciences and Forestry — Ecology and Conservation.