2种微生物药剂防治草原蝗虫的应用研究

为考察不同剂型金龟子绿僵菌对青海地区草原蝗虫的防治效果,开展绿僵菌油悬浮剂和绿僵菌可湿性粉剂对草原蝗虫的防治试验。绿僵菌油悬浮剂和绿僵菌可湿性粉剂各设置3个试验小区,分别为A1、A2、A3区和B1、B2、B3区,A1和B1区为平地,A2和B2区为上坡地,A3和B3区为下坡地,同时设CK对照区;于施药前及施药后第5、10、15、30天对各试验区进行草原蝗虫虫口密度调查,计算施药后第5、10、15、30天的虫口减退率,采用统计学方法对各试验区的草原蝗虫防治效果进行比较。结果表明：施药前各试验处理区的虫口密度与CK对照区差异均不显著（P〉0.05）,绿僵菌2种剂型施药后第5、10、15、30天,各处理区的虫口密度均显著低于CK对照区（P〈0.05）;施药后第10天,A2、A3区的虫口减退率显著高于B1、B2、B3区（P〈0.05）;施药后第15天,A1、A2、A3区的虫口减退率显著高于B1、B2、B3区（P〈0.05）;施药后第30天,6个处理区的虫口减退率均高于65%,绿僵菌油悬浮剂在下坡地施药效果最佳,虫口减退率达到71.86%。总体来看,绿僵菌油悬浮剂的防治效果略优于绿僵菌可湿性粉剂,且施药于下坡地时防治效果更佳。金龟子绿僵菌2种剂型都具有一定的水平扩散能力,施药当年控制草原蝗虫持续效果较显著。

Evaluation on Control Efficacy of Two Types of Microbial Reagents against Grassland Locust

In this study, a filed trail was conducted to compare the control efficacy of two different formulations（oil miscible flowable concentrate, OF; wettable powder, WP） of the microbial reagent of Metarhizium anisopliae against grassland locust.Three experimental spots were designed for each formulation, designated as A1, A2, A3 spots for OF and B1, B2, B3 spots for WP,respectively. The location of the experimental spots A1 and B1, A2 and B2, and A3 and B3 was selected in plain, uphill and downhill grassland. CK spots were also included in this study. The population density of grassland locust in microbial reagent applied spots and CK spots were investigated before application and at the 5 ^th, 10^th, 15 ^th, and 30 thday post application, respectively.Furthermore, the population decline rate of grassland locust were calculated and statistically assessed to compare the control efficacy of the two different formulations and to determine the spatial characteristics of the control efficacy. The results showed that before application, no significant differences in population density of grassland locust between CK spots and all of the experimental spots were observed（P0.05）, and at the 5^th, 10^th, 15 ^th, and 30^thday post application, both of the OF and WP applied experimental spots had significantly lower population density of grassland locust compared to CK spots（P0.05）; at the 10~（th）day post application, the population decline rate of grassland locust in A2 and A3 spots was significantly elevated compared to the B1,B2 and B3 spots（P〈0.05）; at the 15 thday post application, significantly higher population decline rate was observed in the A1, A2 and A3 spots than the B1, B2 and B3 spots（P〈0.05）; at the 30 thday post application, the population decline rate of the six designed experimental spots（A1-A3, B1-B3） all exceeded 65%, and the best control efficacy was obtained in the OF applied spots locating in downhill grassland with population decline rate of 71.86%. In conclusion, the OF had better control efficacy against grassland locust than WP, and the application of OF in downhill grassland had superior control efficacy; both of the two formulations of microbial reagent of Metarhizium anisopliae exhibited certain horizontal diffusion capacity, and they had sustained and good control efficacy against grassland locust in the current year of application.