Study On The Key Control Factors Of Asian Longhorned Beetle(Anoplophora Glabripennis) Natural Populations

Anoplophora glabripennis Motsch.is an important worldwide quarantine pest,which has affected our country forest health seriously.At present the vast majority of China has been harmed by A.glabripennis.And its natural population has been recovered in 11 nation of Europe and United States.So how to control effectively has become a major problem.In this experiment,the natural population control factors and the natural enemies of the egg stage and young larvae stage were investigated by using the natural population life table and sentiol logs.The main results are as follows:1.The natural enemies and their contribution in the control of this pest in Beijing,Tianjin,Hunchun was searched by dissected the infected wood.The results are as follows:The mortality caused by predator was the maximum proportion in the total mortality caused by natural enemies at all of the three sites.In which the average predation rate was the maximum(65.60%)which was significantly higher than those caused by parasitiods and pathogenic microbes(P=0.0001).The mortality rate of parasitiodsin Tianjin is 16.82%where the parasitic rate is highest in these three sites.Furthermore,the total mortality rate of natural enemies in Hunchunwas only 22.42%.2.The results of parasitoids attracted by sentinel logs showed:the young larvae parasitoids in Beijing and Shanghai were abundant.There were 7 species of parasitic wasps were found in Beijing during the past two years,the total parasitic rate was 11.08%in 2015,while the total parasitic rate was 5.82%in 2016.In addition,6 species of parasitic wasps were found in Shanghai during the past two years,the total parasitic rate was 3.32%in 2015,and the total parasitic rate was 7.72%in 2016.However,the parasitoids were rarely in Hunchun,only one species was found in 2015 and the parasitic rate was only 0.15%.Comprehensive parasitoid species and parasitic rate of all the sites,the Oxysychus sp.parasitic wasp was the highest proportion,the parasitic rate of it was 1.51%in Beijing in 2016 and that of Shanghai was 5.99%,this result may suggesting that Oxysychus sp.is a potential parasitoid for the control of A.glabripennis.3.The main control factor and their development trend in Beijing and Hunchun were analyzed by the method of life table.The main control factors of mature larvae were woodpeckers in Beijing all two years(EIPC17).EIPC17 values were 1.8571 and 1.3274 respectively.The average mortality rate of A.glabripennis in Beijing was 71.98%.The average mortality rate of mature larvae was 40.18%.Meanwhile,the main control factor was predators of the eggs and young larvae stage in Hunchun(EIPC3,EIPC9).EIPC values were 1.1102 and 1.1133 respectively.The mortality of A.glabripennis in Hunchun was 40.94%in 2016.Total mortality was 34.24%of egg and young larva stage.Index of population trend in Beijing was 2.6969 and 3.3996 respectively of two years.Index of population trend was 4.6991 in Hunchun in 2016.4.All of the control factors of two sites were analyzed by key factor analysis,the Morris regression analysis method and regression coefficient bi was used.The results showed the value of decision coefficient(r~2=0.501)and regression coefficient(b_i=1.066)of woodpecker was the max.So the woodpecker is the key factor of the natural population of the pest.