Effects of Rickettsia infection on the ecological characteristics of whitefly Bemisia tabaci
Author of the article:WANG Zi-Qi；LIU Yuan；SHI Pei-Qiong；AN Xuan；QIU Bao-Li
Author's Workplace：Key Laboratory of Bio-Pesticide Innovation and Application, Guangdong Province ; Engineering Research Center of Biological Control, Ministry of Education ; College of Agriculture, Guangdong Ocean University ; Maoming Branch, Guangdong Laboratory of Lingnan Modern Agriculture
Key Words：Bemisia tabaci; symbiotic bacteria; Rickettsia; developmental duration; fecundity; survival rate
Abstract：
[Objectives] To elucidate the effects of infection with the secondary symbiotic bacteria Rickettsia on the ecological characteristics of whitefly Bemisia tabaci. [Methods] Cotton was selected as the experimental plant. Rickettsia- positive (B+) and negative B. tabaci (B–) were allowed to feed on plants for 15 d. Plants on which B+ insects had fed were regarded as Rickettsia persistent plants (C+) and those on which B– insects had fed were regarded as Rickettsia-free plants (C–). The developmental time and survival rate of B. tabaci nymphs feeding on these two types of cotton plants, and their subsequent fecundity and longevity as adults, was quantified and compared. [Results] Rickettsia can significantly shorten the developmental time of B. tabaci. The generational time of the B+C+ and B+C– treatment groups was around 17-18d, whereas that of the B–C+ and B–C– treatment groups was around 21-23 d. Rickettsia can also significantly increase the survival of B. tabaci; survival rates from egg to adult of the B+C+, B+C–, B–C+ and B–C– treatment groups were 75.00%, 70.00%, 56.67% and 41.67%, respectively. Rickettsia also significantly increases the number of female offspring produced by B. tabaci. The number of female offspring produced by the B–C– and B–C+ treatment groups was significantly lower than that produced by the B+C+ and B+C– treatment groups. Furthermore, Rickettsia also affects the longevity and fecundity of B. tabaci. The longevity and average fecundity per female of the B+C+, B+C– treatment groups were significantly greater than those of the B–C– and B–C+ treatment groups. [Conclusion] The symbiosis of Rickettsia in B. tabaci, and the persistence of Rickettsia in cotton plants, benefit the development and survival of whitefly nymphs, increase the number of female offspring produced and improve the longevity and reproduction of whitefly adults. In terms of its influence on B. tabaci biology, the symbiosis between Rickettsia and B. tabaci is more important than the persistence of Rickettsia in cotton plants.