Skip to main content
ARS Home » Southeast Area » Stoneville, Mississippi » Southern Insect Management Research » Research » Publications at this Location » Publication #208723

Title: Comparison of Resistance Levels in Four Population of the Rice Stem Borer, Chilo suppressalis (Lepidoptera: Pyralidae)

item XU, GAN LIU
item Zhu, Yu Cheng

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2007
Publication Date: 1/2/2008
Citation: Yue, P., Cong, F., Wen, M., Li, Q., Wei, J., Xu, G., Jin, L., Zhu, Y. 2008. Comparison of Resistance Levels in Four Population of the Rice Stem Borer, Chilo suppressalis (Lepidoptera: Pyralidae). Pest Management Science. 64:308-315

Interpretive Summary: Dose responses of multiple populations to twenty insecticides were examined in this study. Our results provided not only toxicological information of individual insecticides against an economically important insect but also the background information of resistance development in four different regions. Analysis of LD50 values revealed different efficacy levels for all 20 insecticides, which can be used to accelerate screening and selection of potential alternatives for replacing highly toxic organophosphate insecticides which are currently used for rice stem borer control and are deemed to be phased out soon. Comparison of tolerance levels in four populations revealed potential risk of resistance development to certain insecticides, and then provided the guidelines for strategic development to achieve effective chemical control of the rice stem borer with minimal risk of toxicity to environment and resistance development in target insect.

Technical Abstract: Chemical control is a major strategy for suppressing the rice stem borer, Chilo suppressalis. Due to their high toxicity and increasing resistance development in target insect, many insecticides will be phased out soon. Alternatives with relatively low toxicity are urgently needed to replace traditional chemicals for rice stem borer control. In this study, we examined four field populations of C. suppressalis for their toxicological responses to more than twenty insecticides, including a few low toxicity organophosphates and many novel pesticides. The populations represented four different rice-growing regions (provinces). Inter population resistance levels were also compared. Based on LD50 values, the rice stem borer was most sensitive to avermectins and fipronil, requiring less than one ng insecticide to generate 50% mortality. The stem borers exhibited the least sensitivity to endosulfan and monosultap, requiring more than 1000-folds of dose to achieve the same mortality rate as avermectins and fipronil. Insect growth regulators (IGRs: tebufenozide, JS118) and chitin synthase inhibitors (hexaflumuron and chlorfluazuron) showed great efficacy against C. suppressalis, especially against the populations which have developed resistance to conventional insecticides. Four field populations showed variable tolerance levels to many insecticides. The LYG05 was the most susceptible population with resistance ratios (RR) less than 5-folds when compared with a laboratory susceptible strain. NC05 and GL05 populations exhibited intermediate tolerance levels with RRs up to 19.38-folds and 55.52-folds, respectively. RA05 was the most resistant population to many insecticides with resistance ratios up to 79.78-folds. The results from this study provided valuable information for selection and adoption of new alternative insecticides and for resistance management of the rice stem borer.