|YUE, PING HE|
|JIN, LIANG SHEN|
|WEN, MING CHEN|
|CONG, FEN GAO|
|LI, QIN HUANG|
|WEI, JUN ZHOU|
|XU, GAN LIU|
|Zhu, Yu Cheng|
Submitted to: Pesticide Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2007
Publication Date: 9/1/2007
Citation: Yue, P., Jin, L., Wen, M., Cong, F., Li, Q., Wei, J., Xu, G., Zhu, Y. 2007. Differential Susceptibilities to Pyrethroids in Field Populations of Chilo suppressalis (Lepidoptera: Pyralidae). Pesticide Biochem. Physiol. 89:12-19
Interpretive Summary: The rice stem borer is one of the most economically important insects. Control of this insect relies heavily on chemical insecticides. Organophosphate insecticides have been used for many years, and the insect has developed resistance to the chemicals. It is an urgent need to find alternatives to replace highly toxic organophosphate insecticides. Pyrethroid insecticides have relative low toxicity to animals and environment, but have not been used before for rice insect control. This study was designed to investigate the feasibility of selecting pyrethroids for the rice stem borer control. Dose responses of six populations to 10 pyrethroids were determined. Results of two year studies indicated that the pyrethroids are much more effective than organophosphate insecticides. However, different population had different resistance ratios to different pyrethroids. This study provides valuable information for selecting insecticides and resistance management.
Technical Abstract: To assess the feasibility of pyrethroids for rice insect control, we examined susceptibilities of six field populations of rice stem borer Chilo suppressalis (Walker) to ten pyrethroids using the topical application method in laboratory in 2004 and 2005. Our results showed that the seven pyrethroids with high fish-toxicity were more effective against C. suppressalis than the three compounds with low fish-toxicity. The results also showed that all ten of the pyrethroids were much more effective than methamidophos and monosultap for C. suppressalis control. In addition, we found that susceptibilities of some field populations of C. suppressalis to some high fish-toxicity pyrethroids were significantly reduced, and our results indicated that a Ruian (RA) field population showed a year-to-year variation in susceptibility to most tested pyrethroids between 2004 and 2005. Our data indicated that the tolerance levels increased dramatically in RA population, especially to beta-cyfluthrin and deltamethrin. This study provided the first assessment of resistance to pyrethroids in field populations of C. suppressalis. In addition, a close correlation between resistance ratios to the ten compounds and differences of the structures of these compounds was established in the RA05 population, which was resistant to most of the pyrethroids tested while it was still very susceptible to fenvalerate with no cross resistance. Finally, the feasibility and precaution were discussed in selecting pyrethroids as alternatives to replace high toxicity organophosphates for C. suppressalis control and insecticide resistance management.