Location: Pest Management and Biocontrol ResearchTitle: Baseline Susceptibilities of B- and Q-biotype Bemisia tabaci to anthranilic diamides Author
Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/5/2011
Publication Date: 1/15/2012
Citation: Xianchun, L., Degain, B.A., Harpold, V.S., Marcon, P.G., Nichols, R.L., Fournier, A.J., Naranjo, S.E., Palumbo, J.C., Ellsworth, P.C. 2012. Baseline Susceptibilities of B- and Q-biotype Bemisia tabaci to anthranilic diamides. Pest Management Science. 68:83-91. Interpretive Summary: The sweetpotato whitefly, Bemisia tabaci, is one of the post destructive pests of agriculture worldwide. Two biotypes of this pest (B and Q biotype) are widely distributed and are the most problematic. The Q biotype in particular is resistant to many of the insecticides currently available for control. Resistance evolution in the B type and potential invasion of the Q type could disrupt current IPM programs in Arizona and elsewhere. This study developed baseline responses of multiple populations of B and Q biotypes to two new insecticides (chlorantraniliprole and cyantraniliprole) that have unique modes of actions. The study also attempted to determine if whitefly populations already resistant to several commonly used insecticides might be predisposed to resistance to these new insecticides (cross-resistance). The variations in lethal concentrations killing 50% or 99% of test insects was less than 5-fold and 10-fold, respectively, for both new insecticides. Results also indicated the absence of cross-resistance between the two new insecticides and currently used insecticides. Future variation in susceptibility of field populations to chlorantraniliprole and cyantraniliprole can now be documented based on the average baseline susceptibility of populations tested in this study. Results further indicate that these new insecticides represent additional tools for pest management.
Technical Abstract: Development of pyriproxyfen and neonicotinoid resistance in the B biotype whitefly and recent introduction of the Q biotype are threatening the current whitefly management programs in Arizona. Whether the novel anthranilic diamides chlorantraniliprole and cyantraniliprole can be integrated into the current program to control these pests depends on if these compounds have cross-resistance with pyriproxyfen and neonicotinoids. To address this question, we bioassayed 1 susceptible B biotype strain, 1 pyriproxyfen-resistant B biotype strain, 1 multiply-resistant Q biotype strain, and 15 B biotype field populations from Arizona with a systemic uptake bioassay developed in this study. The magnitude of variations in LC50 and LC99 among the populations tested was less than 5-fold and 10-fold, respectively, for both chlorantraniliprole and cyantraniliprole. There was no difference in LC50 and LC99 for chlorantraniliprole between the pyriproxyfen-susceptible and -resistant B biotype strains. The multiply-resistant Q biotype strain was the least susceptible to chlorantraniliprole, whereas the susceptible B biotype strain was the least susceptible to cyantraniliprole. These results indicate absence of cross-resistance between the two anthranilic diamides and currently used insecticides. Future variation in susceptibility of field populations to chlorantraniliprole and cyantraniliprole could be documented based on the average baseline susceptibility of the populations tested in this study