Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) B-and Q-biotypes are exotic insects in Japan and are consequently regarded as insect pests in agricultural fields. Using B-and Q-biotypes, we investigated the hatching rate, survival rate during the larval stage and the total development period from egg to adult. Whiteflies were allowed to lay eggs on several host plants: cabbage, Brassica oleracea var. capitata; cucumber, Cucumis sativus L.; tomato, Solanum lycopersicum L.; eggplant, Solanum melongena L.; bell pepper, Capsicum annuum cv. grossum; and five cultivars of kidney bean, Phaseolus vulgaris (cvs. Kentucky101, Nagauzura, Morocco, Satsukimidori and Honkintoki), and the effects on the above traits were evaluated. Clear differences between the two biotypes were detected. A particularly important difference was that the B-biotype successfully developed to adults on only one of five cultivars of kidney bean, whereas the Q-biotype was able to utilize all the test plants as hosts regardless of the cultivar. This finding suggests that the determination of host plants in B. tabaci is greatly influenced by not only plant species but also by cultivar. In addition, there is a high possibility that the Q-biotype has the ability to adapt to a wider range of plant species and cultivars compared with the B-biotype.