Comparison Of Effects And Benefits Of 4 Kinds Of Control Techniques Of Pine Wilt Disease

The pine wood nematode epidemic area has been to 16 domestic provinces and cities since the discovery of it in China, resulting in a large area of dead pine trees, hundreds of millions of economic losses. Methods and agents used to control pine wilt disease are various and have different control effects. Methods commonly used in practice are dead trees exclusion, trunk injection, biological control, dusting and attractants trapping, etc. In this paper, we conducted the control experiments in the forest using 4 kinds of methods except for attractants trapping for two years(2013 and 2014) and observed the control effects after one year and two years respectively. The comparative study of 4 kinds of control methods in 3 aspects of control effects, economic cost and ecological benefit was carried out, providing data reference to the control practice.1. The field control experiments were conducted to observe the control effects. The control effects of trunk injection of two agents, 2% emamectin benzoate and 5% acetamiprid, were significant, 91.10% and 80.10% respectively. The control effects of dusting of two agents, 1% thiacloprid microcapsule and 3% thiamethoxam moiety powder, were 72.11% and 68.46%.The control effects of two natural enemy biological control, scleroderma sichuanensis and dastarcus helophoroides, were 28.94% and 21.73%.The control effect of dead trees exclusion was 57.72%.2. Adopting attractants trapping method to monitor the population dynamics of monochamus alternatus within each experimental plot. The number of monochamus alternatus trapped in the sample plots of dusting had a rapid decline and there was no obvious second feather peak. The general trend of population dynamics in the sample plots of trunk injection is similar to the trend in the control, but the number of monochamus alternatus was effectively controlled. The dynamics changes in the sample plots of dead trees exclusion and natural enemy biological control were close to the changes in the control in some time periods, respectively.3. The cost of 667 m2 of four kinds of methods every year on average was compared. The cost of dead trees exclusion in was 168 RMB. The cost of trunk injection, 2% emamectin benzoate and 5% acetamiprid, were 140 RMB and 260 RMB respectively. The cost of natural enemy biological control, scleroderma sichuanensis and dastarcus helophoroides, were 333 RMB and 300 RMB. The cost of dusting was the lowest, 60 RMB, both of them were same.4. The cost-benefit of four kinds of methods, in 2 years, were calculated. The cost-benefit of dead trees exclusion was 1-0.87. The cost-benefit of 2% emamectin benzoate trunk injection was the highest, 1-1.48. Another one trunk injection had the 1-0.67 return. The cost-benefit of dusting of two were 1-0.74 and 1-0.73 respectively. The returns of two natural enemy biological control were the lowest, 1-0.18 and 1-0.13.In conclusion, the method, trunk injection, had the best control effect, followed by dusting control. Dead trees exclusion had a certain control effect as the basic control method. The natural enemy biological control didn’t achieve good control effects and still need further exploration and specification to fully play its environment and eco-friendly role in control practice. Emamectin benzoate trunk injection could be popularized and used in practical control, because of the good effect, long efficacy duration and balanced performance in other aspects.