Studies On The Relationship Between Parasitism And Stand Factors And The Effective Accumulated Temperature Of Anastatus Sp.

Anastatus spp.are an important natural enemies for the use of crop or forest pests,Some species have great potential to exploit.In the forest conditions,Parasitism of pest insects was closely related to stand factors.However,The search for major correlation factors and their analysis has been a problem for researchers.Meanwhile,It is important to understand the development starting temperature and effective accumulated temperature of specific species for the future use of pest control.The author use egg kards maded from Antherea pernyi Guerin-Meneville trapping Anastatus sp.of parasitism in different forests Dunhua,Helong,Wangqing,Yanji,in order to study the effects of environmental factors on forest Anastatus sp.parasitic effects.On the basis,Using rough set theory,The weight of environmental factors influencing of Anastatus sp.parasitism.The results shows that the weight of the forest age,the canopy density,the slope and other indicators of rough set theory to determine 0.263,0.368,0.368 respectively,the root mean square error(RMSE)is 1.081.Analysis shows that the forest age,the crown density and the slope in forest stand factors,are more largerinfluence on Anastatus spp.parasitic rate.Rough set theory is more accurate than Delphi method,in which RMSE is improved by 2.172%.Rough set theory has more practical value.In order to make more the efficient use of Anastatus sp.controlling the leaf insect pests of forests,the developmental threshold temperature and the effective accumulated temperature by using regression linear method,direct optimal method and minimum coefficient of variation method of three methods.Based on the comparison of the three methods,the developmental threshold temperature and effective accumulated temperature were calculated.The advantages and disadvantages of the three methods were analyzed and the developmental threshold temperature and effective accumulated temperature were determined.Predicting Anastatus sp.numbers and the possibility of realizing the application of Anastatus sp.in Jilin province.The results showed that the developmental threshold temperature was(8.28 ± 0.3)? and the effective accumulated temperature was(340.43 ± 8.5)day,using the regression linear method.Direct optimal method to calculate development starting point temperature of Anastatus sp.is 8.38?,the effective accumulated temperature of 336.40 degrees.Minimum coefficient of variation method calculation of Anastatus sp.development starting point temperature is 8.35?,the effective accumulated temperature of 337.01 degrees.Three methods respectively to calculate Anastatus sp.development starting point temperature and effective accumulated temperature,by comparing the variation coefficient values of the three methods,the error of development starting point temperature and the effective accumulative temperature of Anastatus sp.were determined by the three methods.By observing the discovery: the variation coefficient of the regression linear method is 2.608,the variation coefficient of direct optimal method is 2.319,the variation coefficient of minimum coefficient of variation method 2.315.The results showed that the smallest variation coefficient of development starting point temperature and effective accumulative temperature were calculated by using the minimum coefficient of variation method.