Induced defense by Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) in tobacco against Myzus persicae (Hemiptera: Aphididae).

Myzus persicae and Bemisia tabaci are serious pests of tobacco and can occur simultaneously on the same plant. We found that tobacco plants infested by whiteflies had fewer aphids than those without whiteflies. To determine whether B. tabaci feeding could induce plant defense against aphids locally and systemically, we determined the effects of B. tabaci on several biological parameters of M. persicae on tobacco. Infestation of B. tabaci nymphs reduced survival rates of M. persicae by 30.0%. In three generations, M. persicae populations increased 1,091-fold on uninfested plants compared with 222-fold on the plants with whiteflies. On the upper leaves with systemic damage but uninfested B. tabaci, the survival rate of aphids was 9.3-fold lower than that on plants that were never been infested by whitefly. Survival rates of M. persicae on leaves with whiteflies present or with whiteflies removed were also lower than those on uninfested leaves. Fecundity of M. persicae was not different on leaves with whiteflies, with whiteflies removed or uninfested leaves; however, fecundity on leaves with systemic damage was lower than on uninfested leaves. Growth rates of M. persicae on the leaves with whiteflies, or with whiteflies removed, were higher than on uninfested leaves, whereas it was lower on systemically damaged leaves than on uninfested leaves. The development of M. persicae was approximately 1 d longer on systemic leaves with whiteflies than on uninfested leaves. These results indicate that feeding of B. tabaci induced a defense in tobacco plants against M. persicae, both locally and systemically, although other mechanisms may also be involved.