Class Insecta: Insects » Order Hymenoptera: Ants, Bees & Wasps » Family Tenthredinidae: Common Sawflies » Euura proxima (Serville, 1823)
Size up to 12 mm long by up to 6 mm wide.
The sawfly Euura proxima is the cause of these fairly large and distinct shiny red, bean-like galls which projects from both surfaces of narrow willow (Salix) leaves, notably White Willow (Salix alba) and Crack Willow (Salix fragilis). Each gall usually contains a single larva, which feeds on the leaf tissues within. There are 2 broods per year.
Fairly common and widespread throughout Britain.