| Bursaphelenchus xylophilus (steiner & Buhrer)Nickle is one of the most dangerous disease on pines, it harms to P.massoniana,P. thunbergii,P. densiflora and many other pines. Because of these facts such as the great harms, no easy harness, the excessive spreading ways and the wide suitable growing areas, We ranks it as the international quarantined, object. Since the first discovery of this disease in Nanjing in 1982, there are 80 countries and cities occurs this disease, the area has reached 118 000 mu. Zhanggong in Ganzhou of Jiangxi Province(east longitude 114°461～115°04~1, north latitude 25°40~1～25°58~1), People discovered this disease in 2003, it was ranked as epidemic area in 2004, The National Forest Bureau effected it into harness project. Aim at the need of the examination on Bursaphelenchus xylophilus (steiner & Buhrer)Nickle, explore the life story on medium insectMonochamus. alternatus; Bursaphelenchus xylophilus (steiner & Buhrer)Nickle resulted in the trees driedup and died next year, These research in Ganzhou on the law of this disease in order to discovery the disease and control the source of the disease as soon as possible to satisfy the needs of practical production may offer the basis for diagnosis, prevention and harness.The research indicates that: Monochamus. alternatus in Zhanggong county in Ganzhou arises 1～2 eras every year, mainy 1 era, 2 eras are very few, about 2%; 92～93% of them live through the winter as 2～4 years grub under the bark and in the xylem. the grub can keep activity when the tempreture higher than 10～13℃. It can be reactive in March next year, continues getting foods, and starts to pupate on the first ten days of April, the prosperous days of pupating is from the last ten days of April to the first ten days of May, the end of pupating is the middle ten days of April, The first generation keeps pupating from the last ten days of September to the middle ten days of November, it finishes its pupation in the last ten days of November; the period of eclosion is from the last ten days of Aprii to August, popular in May and June, the first generation is-from the first ten days of October to the first ten days of November; the imago can be found from the middle ten days of April to the first ten days of November; the grubs all around the years, there are -the alternation phenomenons, the spawn on wood which has died leaves is higher than wood which has no leaves, this indicates that the branch and died leaves have attracting effect to the spawn of Monochamus. alternatus.The research approves that: in ganzhou city, Bursaphelenchus xylophilus (steiner & Buhrer)Nickle is most likely to harm the big Pinus massoniana which are older than 15 years, the symptom of disease is most likely to appear from the middle ten days of July to Semtember, there are Pinus massonianarom dead from May to December, the occurance and development of disease, are related to the weather and pests such as high temperature and dry day. the Monochamus. alternatus,Lps sexdentatus Boerner,Pissodes alidirostris Gyllenhyl and so on. These disadvantage of pine will develop the disease.The research approve that: P. elliottii,P.taeda,P. massoniana all have the diseasde tree with the symptom of deadwood and dried up to dead next year. the symptom of deadwood and dried up to dead next year is related to the age of the P. massoniana, The P. massoniana of 15 years to 20 years all occur these symptom. The symptom on P. massoniana of deadwood and dried up to dead next year is related to the shape of the tree and the deep of the cortex, the P. massoniana which has thick peel and narrow and density coronal is more likely to infect the disease than the P. massoniana which has thin peel and narrow and scanty coronal, the symptom of deadwood and dried up to dead next year is related to the degree of the danger by the pests. Whether there are few or more branch-eaten pest is very important.
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