棉 花 学 报     Cotton Science    2006，18(3)：164-169

 

 

Monitoring and Risk Assessment of Resistance to Tebufenozide in Spodoptera Exigua
JIA Bian-tao1，SHEN Jin-liang1*，LIU Yong-jie2
(1.Key Laboratory of Monitoring and Management of Plant Diseases and Insects，Ministry of Agriculture ， Department of Pesticide Science，College of Plant Protection，Nanjing Agricultural University，Nanjing 210095，China；2.Department of Plant Protection，Shandong Agricultural University，Tai'an，Shandong，271018，China)

Abstract：Resistance of the beet armyworm to many insecticides has been documented in many areas. Tebufenozide, the first commercial non-steroidal ecdysteroid agonist, proved to be extremely potent against and selective toward larval Lepidoptera,and has been recently widely used against Lepidoptera pests on several crops in China. Monitoring and risk assessment of resistance can provide information that will be useful for pro-active management of resistance for this valuable group of insecticides. Susceptibility to tebufenozide of the beet armyworm from Fengxian, Dafeng, Sheyang, Funing, Jiangning of Nanjing, Jiangsu Province and Xinye, Henan Province were determined through exposure of the first instars of dipped cabbage leaves. The results showed six field populations were susceptible to or had decreased susceptibility to tebufenozide (2.1-4.2 folds). A field population from Shenzhen, Guangdong Province was tested in the laboratory with one concentration (survival percentages ranged from 40% to 80% at 3 d after exposed each generation) of tebufenozide incorporated into an artificial diet for 34 generations. The LC50 of selected strain was 17.0 times less susceptible to tebufenozide, when compared with the original reference strain. Estimation of realized heritability (h 2) of resistance was based on the method described by Tabashnik & McGaughey. The results suggested that h 2 to tebufenozide was lower in the first half （1～17 generations ） of the selection experiment (h 2=0.1021) than in the second half (18-34 generations) ( h 2=0.1519). h 2for the entire selection experiment was 0.1695. Assuming h 2=0.1021 and selection kills 80% ~90% of the populations, then a 10- fold increase in LC50 was expected in 14-18 generations. These results demonstrated the beet armyworm may have lower chance of resistance development to tebufenozide. At the same time, resistance management of beet armyworm was discussed.
Key words：Spodoptera exigua；tebufenozide；resistance monitoring；realized heritability；
             risk assessment         [Full Text,2509KB]