Feeding Experience Affects Behavior And Fitness Of Bemisia Tabaci (Hem1p I Era: Aleyrodidae) And Its Symbiotic Association

The whitefly, Bemisia tabaci (Gennadius)(Hemiptera: Aleyrodidae) is a sibling speciesgroup, and they infest at least600plant species. B. tabaci biotype B is the most notorious one.Prior to this study, little has been known about the host selection behavior of host plantexperienced whitefly populations. In this study, we established three whitefly populations,namely, Bemisia-eggplant, Bemisia-tomato and Bemisia-cucumber through feeding thewhiteflies over several generations on eggplant, tomato and cucumber, respectively.Subsequently, we evaluated the responses of whiteflies to host plants for feeding andoviposition of adults, development and survival of immatures of those feeding experiencedwhitefly populations on their experienced natal host plant and other host plants (eggplant,tomato, cucumber and pepper) on which there had no previous experience. Resultsdemonstrated that the influence of previous experience of the whiteflies varied among thepopulations. All three populations clearly refused pepper for feeding and oviposition butBemisia-cucumber and Bemisia-eggplant strongly preferred cucumber, whereas the Bemisia-tomato did not show a strong preference to any of the three host plants. Development timefrom egg to adult eclosion varied among the populations, being shortest on eggplant, longeston pepper, and intermediate on tomato and cucumber except for the Bemisia-cucumber whichdeveloped similarly on tomato and pepper. The survivorship from egg to adult eclosion of allpopulations was highest on eggplant lowest on pepper, and intermediate on tomato andcucumber. We also analyzed the endosymbionts of Bemisia-eggplant, Bemisia-tomato andBemisia-cucumber qualitatively and quantitatively. We transferred whitefly adults from natalhost plants to new host plants, reared them from egg to adult eclosion, and quantified theirendosymbionts. We also measured the amino acid compositions in host plants and whiteflypopulations. Results showed that host plant affects the endosymbionts quantitatively but notqualitatively. The quantity of primary endosymbiont increased or decreased based on the lower or higher concentrations of total essential amino acids in the host plants, respectively.All together, the effects of previous experience of whiteflies on host selection for feeding andoviposition, development, and survivorship varied depending on host plants, and host plantsplayed a stronger role than previous experience. Preference for feeding and oviposition byadults might not accurately reflect host suitability of immatures. qRT-PCR results ofendosymbionts suggest that host insects may manipulate its endosymbiont quantity accordingto their physiological requirement. These results will provide important information forunderstanding whitefly population dynamics with their dispersal among different cropsystems and the associations among symbionts, insects, and plants.