STATUS OF INSECTICIDE RESISTANCE OF THE WHITEBACKED PLANTHOPPER, SOGATELLA FURCIFERA (HEMIPTERA: DELPHACIDAE).

Frequent outbreaks and widespread transmission of rice black-streaked dwarf virus by Sogatella furcifera (Horváth) (Hemiptera: Delphacidae) have aggravated yield losses of rice in eastern China. The use of insecticides for suppression of the vector has been a fundamental approach to prevent epidemics of the virus disease. However, the status of insecticide resistance in S. furcifera has not been examined recently in China. In this study, dose responses of S. furcifera to buprofezin, imidacloprid, thiamethoxam, chlorpyrifos and pymetrozine were evaluated. Most populations in eastern China have developed moderate resistance to buprofezin (up to 25-fold). Approximately 32% of field populations exhibited moderate resistance to imidacloprid, while other field populations showed minor changes (7.6-fold) in their susceptibility to this insecticide. Low variation of susceptibility to thiamethoxam (<6-fold) was observed among field populations, and no obvious resistance to this product was observed. Obvious variation (10.2-fold) of susceptibility to chlorpyrifos existed in field populations of which 8% displayed moderate resistance, and 32% exhibited low level resistance. Most populations (72%) were susceptible to pymetrozine, and relatively low variation of susceptibility to it was detected among the field populations of S. furcifera. Frequent and extensive use of buprofezin had driven the rapid development of resistance, and buprofezin resistance is widespread in the field populations of S. furcifera in China. To prevent further development of the resistance, use of buprofezin should be limited and rotated with alternative insecticides with different modes of action. [ABSTRACT FROM AUTHOR]