Spatial Distribution And Control Techniques Of Arhopalus Rusticus(Linnaeus)

Arhopalus rusticus is an important wood-boring pest that can cause considerable damage to species of the genera Pinus,Cunninghamia,and Cupressus,which has the strongest possibility of supporting Bursaphelenchus mucronatus and Monochamus alternatus.It can also spread long distance with logs and wooden package,endangering the import and export trade of coniferous forests and threat.To determine the spatial distribution of its population,spatial characteristics were analyzed using Go-statistical methods for A.rusticus,through screening suitable pesticides and field trapping experiments,we studied the volatile organic compounds in host plants of Arhopalus rusticus,and proposed.In order to study the effective plant source attractant of Arhopalus rusticus,we hope to monitor and capture the technical basis of Arhopalus rusticus.Spatial characteristics were analyzed using Go-statistical methods for A.rusticus larvae and adults in three Pinus tabulaeformis woodlands with different levels of damage.The results showed that the degree of damage caused by A.rusticus differed significantly in the three woodlands.In lightly infested woodland,30.8%of trees were infested,whereas 44.3%and 78.3%of trees were infested in moderately and heavily infested woodlands,respectively.Isotropic variogram analysis indicated that Gaussian models were suitable for simulation of the spatial distribution of A.rusticus larvae in lightly and moderately infested forests,while,the Exponential models were suitable for heavily infested forests.In contrast,linear models were suitable for simulation of the spatial distribution of A.rusticus adults in lightly,moderately,and heavily infested forests.The quantity of larvae showed evident spatial dependence in the three woodlands.Analysis of the vertical distribution of A.rusticus indicated that larvae and adults preferred to congregate at a certain height in Pinus,whereas above and below this height,the density decreases.In lightly infested woodland,the largest number of larvae were found at a height of 24-25 cm,whereas the largest number of adults was found at a height of 4-5 cm;in moderately infested woodland,the largest number of larvae were found at 9-10 cm and the largest number of adults at 26-27 cm;and in heavily infested woodland,the largest number of larvae were found at 13-14 cm,and the largest number of adults at 5-6cm.Experiments were conducted on control of Arhopalus rusticus used by two pesticides(8%cypermethrin 3%Thiacloprid).The results showed that 300 times diluent of 8%cypermethrin and 1000 times diluent of 3%Thiacloprid are the more effective concentration.The control effect of two pesticides on Arhopalus rusticus were studied by experiment on Arhopalus rusticus in cage in forest.The results showed that the adjusted mortalities of 300 times diluent of 8%cypermethrin and 1000 times diluent of 3%Thiacloprid were 96.7 percent 1 day after the treatment.The adjusted mortalities of the 8%cypermethrin 3%Thiacloprid were 75 percent and 71.7 percent respectively 3 1 days after the treatment Therefore,it is recommended that the application should be repeated once within 1 month after application to ensure effective control of the Arhopalus rusticus adultsIn order to screen the attractants of the Arhopalus rusticus,this study was directed to the habit of weakening Pinus by Arhopalus rusticus adults.Using plant volatile compounds used for baiting Arhoplus rusticus in the fields.The results indicated that the mixture attractants had a certain ability to trap Arhopalus rusticus,among which,Kl,J1,K3,N5 and N1 had a comparatively stronger effect than other attractants.K1,J1,N1,N5 and L6 showed significant effect on male lures.This study proves that the self-developed attractants have a good effect on the adults of the Arhopalus rusticus,and can be used to monitor and control this adult,which provides a theoretical basis for its scientific control.The study was carried out on oviposition selectivity of Arhopalus rusticus adult.The results showed that the fecundity of the females was as follows:Pinus tabulaeformis>Pinus sylvestris var.>Larix gmeliniithe order of size was 7cm>5cm>3cm.The fecundity of females on Pinus tabulaeformis and Pinus sylvestris var.was significantly different from that of larch wood,but the difference was not significant on Pinus tabulaeformis and Pinus sylvestris.