|Zhu, Yu Cheng|
|ZHANG, JIUSHUANG - Nanjing Agricultural University|
|LI, WENHONG - Nanjing Agricultural University|
|DAI, DEJIANG - Nanjing Agricultural University|
|LIN, YOUWEI - Nanjing Agricultural University|
|ZHOU, WEIJUN - Nanjing Agricultural University|
|SHEN, JINLIANG - Nanjing Agricultural University|
Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2008
Publication Date: 5/12/2008
Citation: Wang, Y., Gao, C., Zhu, Y., Zhang, J., Li, W., Dai, D., Lin, Y., Zhou, W., Shen, J. 2008. Buprofezin susceptibility survey, resistance selection and preliminary determination of the resistance mechanism in Nilaparvata lugens (Homoptera: Delphacidae). Pest Management Science. 64(10):1050-1056.
Interpretive Summary: Buprofezin exerts its insecticidal effect through inhibition of chitin synthesis, a key component of insect body armor. Buprofezin is especially effective against Homoptera pests, such as the planthopper, with very low risks to environment and human. Buprofezin is recently recommended as one of the alternatives for replacing highly toxic organophosphorous insecticides for controlling economically important insects on rice. The results from this study cautioned that the planthopper is able to achieve an extremely high level of resistance to nullify the effectiveness of buprofezin. Eleven-year resistance monitoring data exhibited that resistance ratio in the planthopper tended to increase over the 11-year period. Relatively slow speed of the resistance development may attribute to some influential factors, such as the recessiveness and fitness costs of the resistance and migratory nature of the insect. Reducing selection pressure on target insect through rotation with other functionally different insecticides might be a key component for delaying and minimizing resistance risk.
Technical Abstract: Buprofezin has been used for many years to control the brown planthopper, Nilaparvata lugens (Stål) in China. To provide resistance assessment for national resistance management program, we collected a total of 45 samples of the planthopper from 27 locations across eight provinces for monitoring their dose responses and susceptibility changes to buprofezin over an 11-year period (1996-2006). Results showed that N. lugens from 16 field populations were susceptible to low levels of resistance to buprofezin with 1.5-3.5 fold resistance ratios before 2004. However, substantially higher levels of the resistance (up to 28-fold) were found in most of rice fields in China after 2004. A field population of N. lugens was collected and periodically selected for buprofezin resistance in laboratory. After a total of 53 generations (44 were selected; F6-F9, F15-F17, and F19-F20 were unselected), the colony successfully obtained 1658.2-fold resistance to buprofezin. Relative fitness analysis using life tables showed that buprofezin resistant colony had obvious disadvantages in their reproduction and development. The fitness of a highly resistant colony decreased dramatically (0.58) to a level of almost one half of that of a susceptible strain. The results from this study indicated that N. lugens had a potential to develop high resistance to buprofezin, but reduced fitness in buprofezin-resistant insects could result in a quick recovery of population susceptibility if the selection pressure is removed. Therefore, a practical resistance management program with rotation of buprofezin and other pesticides may efficiently delay or slow down resistance development in N. lugens.