| The Monochamus alternatus Hope is the main vectors of Bursaphelenchus xylophilus.Pine wilt disease was found in China in 1982,it had caused large area death of pine plantations,causing huge economic losses.We chose Ma'anshan forest farm which the disease broke out earliest and most serious as study plot.In this thesis, the Influence of forest stand factors on the amount of Monochamus alternatus and the condition of nutrition supply of Monochamus alternatus were studied for the control of the Pine Wilt Disease in the near future and the more understanding of the relation between pine,Monochamus alternatus and Bursaphelenchus xylophilus.The result Was:1.The relation between forest stand factors and the amount of Monoehamus alternatus displayed in the following six aspects:(1)Forest types:there were six main forest types:the pure P.thunbergii forest,the pure P.massoniana forest,the pure P.teada forest,the mixed P.massoniana and P.thunbergii forest(7:3),the mixed P.massoniana and P.thunbergii forest(4:6),the mixed P.massoniana and P.thunbergii forest(5:5),the difference of the amount of Monoehamus alternatus between forest types was not significant(F=1.67,P=0.1660)(2)Ground coverage rate:the average amount of ground coverage rate(＞30%) and ground coverage rate(＜30%) was 39.9 and 76.2 respectively,the difference of the amount of Monochamus alternatus between ground coverage rate(＞30%) and ground coverage rate(＜30%) was extremely significant(F=16.02,P=0.0003)(3)Shade density:the average amount of shade density(＞70%) and shade density (＜70%) was 49.5and 52.4 respectively,the difference of the amount of Monochamus alternatus between shade density was not significant(F=0.09,P=0.7666)(4)Aspects:the ratio of the amount of Monochamus alternatus in the south to the amount in the north is 2.5:1,the amount of Monochamus alternatus in the south is obviously larger.The difference of the amount of Monochamus alternatus between south and north was significant(P=2.32,F=0.0378). (5)Location in the forest stands:The average amount of Monochamus alternatus between the edge of the forest stands and the middle of the forest was 60.3 and 41.0 respectively.The difference of the amount of Monochamus alternatus between south and north was significant(F=4.29,P=0.0447)(6)Elevation in the forest stands:The average amount of Monochamus alternatus between high altitude localities and low altitude was 52.7 and 48.9 respectively.The difference of the amount of Monoehamus alternatus between high altitude localities and low was not significant(P=0.15,F=0.7003)。2.The study of the condition of nutrition supply of Monochamus alternatus involved four aspects:(1)Comparison of the preference of Monoehamus alternatus between tree species: the average feeding area of one-year-old branch of P.thunbergii Parl.,P.massoniana Lamb,P.taeda was 39.13,23.24,17.14,the difference was not significant(F=1.11, P=0.3439),the average feeding area of two-year-old branch of P.thunbergii Parl.,P. massoniana Lamb,P.taeda was 34.3,5.44,7.84,the difference was significant(F=3.86,P=0.0341).(2)Comparison of feeding area between one-year-old branch and two-year-old branch:the average feeding area of P.thunbergii Parl.of one-year-old branch and two-year-old branch is 38.6cm2 and 34.3cm2,the difference was not significant(F=0.04,P=0.8467);the average feeding area of P.massoniana Lamb of one-year-old branch and two-year-old branch is 23.24 cm2 and 5.44cm2,the difference was significant(F=6.21,P=0.0216);the average feeding area of P.taeda of one-year-old branch and two-year-old branch is 17.14 cm2 and 7.84cm2,the difference was not significant(F=4.02,P=0.0601)(3)the Influence of the diameter of the branch to the feeding area of Monochamus alternatus:as the diameter became small,the feeding aera became small,but there is no rule but has exceptions.Some branch have maximum diameter but didn't have the maximum feeding area.(4)Comparison of feeding area between Monochamus alternatus Hope carried Bursaphelenchus xylophilus and not:the difference of feeding area between one-year-old branch and two-year-old branch is not significant.
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