| Co-Investigator(Kenkyū-buntansha) |
MAKIHARA H For & For.Products Res.Inst, Insect Ecology, Lab.Head, 森林生物部昆虫生態研究室, 研究室長
IWATA Ryutaro Nihon University, College of Bioresource Science, Lecturer, 生物資源科学部, 教授 (90213298)
CHANG Pei Kang Nihon University, College of Bioresource Science, Lecturer, 生物資源科学部, 講師 (90256834)
NATORI Masahiko Nihon University, College of Bioresource Science, Professor, 生物資源科学部, 教授 (80059203)
OBA Kihachiro Tsukuba Univ., Instit.of Agriculture & Forestry, Professor, 農林学系, 教授 (80176982)
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| Research Abstract |
Heavy infestations of pines have been occurring for decades in Japan, caused by the pine wood nematode (PWN) and its vector, the Japanese pine sawyer (JPS), Monochamus alternatus hope PWN was thought to be introduced from the New World with imported timbers in some time. The original distributions and relationship among the related nematode species have been studied through crossing and DNA analysis, and the origin of PWN invaded to Japan has been well illustrated. As for the vector, JPS is endemic and distributed widely in Japan, and also in East Asias. The invasion and expansion of the heavy infestations to uninfested areas have been mainly caused by the movement of JPS,by themslves naturally, or by artificial movement of the infested pine logs for utilization in which the larvae are breeding. Morphologically JPS in Japan is not different among regious, but JPS in Taiwan is different from those in Japan, as following : Taiwanese and Chinese populations : one pair of rusty longitudinal stripes on pronotum distinct ; elytra with balck markings, granules around the anterior angle large, anterior median carina distinct. For prevention of pine mortality by controling PWN and JPS,occurrence of JPS emergence is the most essential, of which time is dependent on the eco-physiological characteristics of the populations and environmental conditions. The population in Taiwan does not need hibernation to complete its generation, but JPS in Japan needs hibernation and to break the diapause low temperature is required.
The report is to elucidate whether there are some differences among the populations besides morphological and eco-physiological points, and hope to contribute further taxonomy of the sawyers in and outside Japan. Esteraze isozymes of JPS of various origin were analyzed, and it is showed that JPS in Taiwan and main land China have quite different isozyme patterns from those in Japan, suggesting their taxonomical differences.
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