Distributing PWN In Pinus Massoniana And Analysis Of Environmental Factors Impacting Adulthood Duration Of Monochamus Alternatus Hope

Worldwide destructive pine wilt disease(PWN)of critical importance in Chinese forestry management and quarantine.Its only pathogen Bursaphelenchus xylophilus(pine wilt nematode,PWN)has ability to spread widely with the coordination of vector beetle Monochamus alternatus Hope.Revealing the pathogenesis of PWN and the population dynamics of M.alternatus can provide effective theoretical basis for systematical monitoring and integrated control of PWN and M.alternatus.On the one hand,morphological identification and PCR molecule detection were applied to confirm the exist of B.xylophilus,then its spatial-temporal distribution in infected Masson pine along with morbidity process was simulated.On the other hand,we used attractant traps to monitoring M.alternatus in Fujian Province for continuous 2a.Next,the effect of environmental impactors on M.alternatus' adulthood and trapping amount were summarized.The results show that:1.Spatial-temporal distribution characteristics of PWN in P.massoniana at ongoing PWD stagesThe amount and distribution of PWN are dynamically changing with the pathogenic process.At the initial stage,nematodes are rarely seen,and the number of PWN is under detected line.From initial to middle PWD stage,PWNs migrate to whole tree and multiply continuously in a short period.The amount of PWN in different detected parts ranks: upper trunk > primary branches > central trunk > lower trunk > new branches;At late PWD stage,the amount of PWN decrease steady,and its ranks are:upper trunk > primary branches > lower trunk > central trunk > new branches,but there was no significant difference among these parts.In addition,nematodes are also distributed in stumps,taproots and fibrils of P.massoniana,but PWNs only exist in stumps and taproots.2.Seasonal spatial distribution characteristics of PWN during autumn and winterExcept 1~2 year new branches,PWN could be detected during the whole period of autumn and winter.PWN's number in autumn signally out number of that in winter.Besides,PWNs mainly distribute in primary branches of middle crown in autumn,and in primary branches and upper trunks during winter.3.Population dynamics of adult M.alternatus in Fujian ProvinceThe M.alternatus adulthood varies from 140 to 297 d in Fujian Province.Annual average temperature and humidity are the most effective meteorological factors of M.alternatus adulthood.Its length has signal positive correlation with annual average temperature,and negative correlation with annual humidity.Significantly,trapping amount is positively affected by annual average temperature and humidity,negatively affected by annual precipitation and sunshine duration.As for geographical factors,slope direction and latitude have significant effects on adulthood.The adulthood length in different slope directions ranks as: slope top > west slope > east slope >north slope > south slope.Adulthood shrinks with the increasing latitude.Furthermore,altitude posts negative impact on trapping amount.However,Masson pine dominance and canopy density show positive effects.