Leaf-mining insect that attacks various holly species. The larvae feed so slowly that the damage may initially go unnoticed. At first, damage appears as a dark brown spot on the leaf, but as further feeding occurs, this turns into a long blotch by late winter. A heavy infestation may result in the majority of leaves being mined. Prior to egg laying, the adult female stabs the leaf with her ovipositor and both male and female adults feed on the sap that flows from the wound. This action leaves several small puncture wounds in the developing foliage. Spray treatments and/ or soil drench treatments recommended.