Fitness costs and morphological change of laboratory-selected thiamethoxam resistance in the B-type Bemisia tabaci (Hemiptera: Aleyrodidae)
Article first published online: 2 FEB 2009
© 2009 Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences
Journal of Applied Entomology
Volume 133, Issue 6, pages 466–472, July 2009
How to Cite
Feng, Y. T., Wu, Q. J., Xu, B. Y., Wang, S. L., Chang, X. L., Xie, W. and Zhang, Y. J. (2009), Fitness costs and morphological change of laboratory-selected thiamethoxam resistance in the B-type Bemisia tabaci (Hemiptera: Aleyrodidae). Journal of Applied Entomology, 133: 466–472. doi: 10.1111/j.1439-0418.2009.01383.x
- Issue published online: 8 JUN 2009
- Article first published online: 2 FEB 2009
- Received: October 4, 2008; accepted: December 30, 2008.
- Bemisia tabaci;
- fitness costs;
- insecticide resistance;
Thiamethoxam has been used as a key insecticide to control the whitefly, B-type Bemisia tabaci, for several years in China with no known cases of resistance in field populations. To evaluate the risk of resistance, a field population was collected and resistant strains were developed by exposure to thiamethoxam in the laboratory. After selection for 36 generation, a strain with 60-fold resistance was successfully identified. Fitness analysis by constructing life tables, demonstrated that resistant B-type whiteflies had obvious fitness disadvantages in their development and reproduction. The fitness of resistant B-type whiteflies decreased dramatically, to only one-half that of the susceptible strain. Some changes in the morphological characteristics of the resistant strain were observed. The lengths of first, second and third instars of the resistant strain were significantly smaller than those of the susceptible strain, and the width of the first and the fourth instars were also significantly smaller than in the susceptible strain. Our results suggest that the B-type B. tabaci has the potential to develop high resistance to thiamethoxam, and that the resistance changed the morphology of the insects. The slow development of resistance and the lower fitness of resistant B. tabaci strains may result in a quick recovery of sensitivity when the population is no longer in contact with thiamethoxam in the field.