Phyllonorycter rajella

Description

Phyllonorycter rajella is a moth of the family Gracillariidae. It is known from all of Europe, except the Iberian Peninsula and Greece. The wingspan is 7–9 mm. There are two generations per year with adults on wing in May and again in August. The larvae feed on Alnus cordata, Alnus glutinosa, Alnus incana, Alnus oregona and Alnus viridis, mining the leaves of their host plant. They create a lower-surface tentiform mine, usually in the axle of a thick lateral vein and there is one strong lengthwise fold. Pupation takes place in a tough off-white cocoon that is attached to the floor and the roof of the mine. Most frass is incorporated in the sides of the cocoon.