Effect of wire netting method, which had been previously proved to be effective for preventing A. malasiaca oviposition in a young citrus grove, was examined in a mature citrus grove. The following 3 treatments were tried in a grove of 285 trees; (1) netting the tree trunk and piling up soil around the trunk base, (2) netting the tree trunk but not piling up soil around the base, and (3) untreated (control). The proportion of oviposited trees, the mean number of eggs and larvae, percentage of living eggs, and proportion of trees bored by larvae were compared among these treatments. The wire netting proved effective in preventing injuries by A. malasiaca, and further improved by guarding the trunk base with soil.