Fenusa pusilla
Fenusa pusilla is also known as the birch leafminer. It is a European sawfly and was accidentally introduced to North America before the early 1920s. The larva feeds within blotch mines in the leaves of birch trees and overwinters as a prepupa. Depending on the area, F. pusilla can produce one to three generations per year.
Order: Hymenoptera
Family: Tenthredinidae
Species: Fenusa pusilla
Photograph: © 2007 RKD Peterson
Date of Photograph: 12 August 2007
Location: Montana, Gallatin Co. (45o43'41" N 111o08'11" W)