Definition
Fenusa pusilla, commonly known as the birch leafminer, is a species of sawfly whose larvae feed inside the leaves of birch trees. These larvae create noticeable blotch-like mines within the leaf tissue. Heavy infestations can cause premature leaf drop and weaken the tree. *Fenusa pusilla* is considered a pest in many regions where birch trees are cultivated. Think of it as a tiny, leaf-bound vacationer with a destructive appetite. 🐛