Numeric Dynamics Of Monochamus Alternatus Adults In The Southwestern Of China And Altitude's Effects

Monochamus alternatus is a native borer infesting pine forest and the main vector of pine wilt disease in China.It was well proved that an effective method to suppress pine wilt disease was controlling M.alternatus population in the past 30 years.So it was important for establishing a scientific IPM scheme to explore and clarify of the dynamics of M.alternatus population.In this paper,the temporal dynamics of M.alternatus adults were investigated in Chongqing,Sichuan,Guizhou and Yunnan,using traps baited with APF-I chemical attractant.1.The field investigation showed that differences were often observed in the numeric dynamics of M.alternatus adult caught by traps in different districts.The adult number peaked from the end April to end June in Dadukou of Chongqing in a whole year.However it peaked from the early May to early July in Jiulongpo,from the middle of May to early July in Banan,Nanan,Jiangjin and Tongliang,from the middle of May to middle of July in Liangping,Yubei and of Jinyun mountain,from the middle of May to end July in Qijiang,from the middle of May to early August in Xiushan and Yongchuan,from the middle of May to the middle of August in Rongchang,from the end May to the middle of July in Nanchuan and Yunyang,from the end May to early July in Wangsheng,from the end May to early July and from the end July to early August in Bishan,from the end May to end July in Shizhu and Fengdu,from the early June to the middle of August in Kaixian,from the early June to early August in Shapingba;,and from the middle of June to early July in Wangzhou.In Sichuan province,the peak of adults was found from the middle of May to end July in Fushun and from the end June to the middle of August in Yibin,hwoever,it was from the early June to the middle of July in Huichuan and from the middle of June to early September in Tongzi of Guizhou province.2.In order to explore the effect of altitude on M.alternatus adults' temporal dynamic,trapping experiment at different altitudes was also conducted in Yulong of Yunnan province in this paper.The result showed that M.alternatus adult was alive and trapped at the pine forest stand with altitude of 2,830 m,but no adult was found in the forest stands with altitude of 3,070 m or beyond.It implied that the limit altitude of M.alternatus distribution might be between 2,830 and 3,010 m.Altitude had a significant effect on the number of M.alternatus adults.The amount of adults captured by traps significantly decreased with altitude increasing,and altitude,month and their interactions all exhibited remarkable effect.