Pathogen infection病原体への感染 Pathogen infection refers to the process in which microbes such as fungi, bacteria, or viruses cause discoloration or necrosis in leaf tissue, leaving traces in the form of spots or spreading lesions.

Piercing-and-sucking穴あけ吸汁 Piercing-and-sucking refers to a feeding behavior in which an insect inserts slender, needle-like mouthparts (stylets) into a leaf and withdraws plant fluids, such as cell contents or sap from the phloem or xylem.

Skeletonization骨格化 Skeletonization refers to a feeding pattern in which insects scrape away the softer leaf tissue while leaving the tougher veins largely intact.

Surface feeding表面食 Surface feeding refers to a feeding behavior in which an insect scrapes away one side of a leaf, removing the epidermis and part of the underlying mesophyll while leaving most of the leaf’s overall structure intact.