鹿児島県におけるヒノキカワモグリガ（鱗し目：ハマキガ科）の被害状況

Abstract

The cypress bark moth, Epinotia granitalis sometimes causes great damage to timber production of Cryptomeria japonica ("Sugi" in Japanese) and Chamae-cyparis obtusa ("Hinoki"). The larva bores a gallery, feeding on the phloem and the cambium. Then, the xylem under the gallery is stained. A considerable amount of resin is exuded from the infested portion continuously for over a year. Later on, the bark layers on the infested portion protrude into an irregular swelling, of which the outer layer frequently peels and cracks transversely. Therefore, the commercial value of the injured timbers is extremely reduced. The percentage of trees injured by the moth was surveyed in November 1986 and June-July 1987 at 24 stands of C. japonica and 8 stands of C. obtusa plantations in Kagoshima Prefecture. At each stand 50 trees were examined to determine the swelling and resin flow, and environmental conditions of the stands were recorded. The injured trees were found at 6 stands of C. japonica and 3 stands of C. obtusa. In particular, the 3 stands of C. japonica in Fukuyama-chô were severely infested. At the remaining 6 stands, the percentage of injured trees ranged from only 2 to 6. Given the particular combination of growing conditions, location and management at the stand, there was no clear tendency for the percentage to increase. However, most of the injured trees were found at the edge of stand or in the stands which are located along a highway. These observations may be suggestive of the habitat preference of the bark moth.