Study on the Biological Characteristic of Monochamus alternatus Hope

s:Monochamus alternatus Hope is main insect invaing pine trunk,and also the dispersal vector of Bursaphelenchus xylophilus observation shows that only the generation occur in a year in Anhui province,it spends its winter in the pupal chamber of the trunk xylem in 3～4 stage larvae,and begins to pupate in the middle and late April.The adults start emerging from hole in the early and middle May,and reach the peak in the middle and late June.It disperses B.xylophilus through crawling and flying and invade 1～2 year old brands and barks of the top trees.After 2～3 weeks,it begins to have a sex and lay eggs within the period ot early June to September.The life of adult is 34～108 days.The sex ratio is about 1∶1.