Four cultivars of broccoli (Brassica oleracea L. variety ‘italica’), two cultivars of early cauliflower (Brassica oleracea L. variety ‘botrytis’), four cultivars of late cauliflower, and one cultivar of red cabbage (Brassica oleracea L. variety ‘capitata’) were screened to determine some reproductive parameters of Aleyrodes proletella L. in a no-choice assay. The highest and lowest oviposition rates and production of pupae and adults were obtained with late cauliflower (cultivar Picasso) and red cabbage (cultivar Cabeza negra), respectively. The highest percentages of adult emergence (indicating survival from egg to adult) were obtained on broccoli (cultivar Chevalier) and late cauliflower (cultivars Mayfair and Picasso), whereas the lowest was obtained on late cauliflower (cultivar Arbon). In a choice experiment, A. proletella preferred late cauliflower (cultivar Picasso) and broccoli (cultivar Agripa) to red cabbage (cultivar Cabeza negra). Significantly more adults per day, and more pupae and empty pupal cases per plant, were found on broccoli and cauliflower cultivars than on red cabbage. In another no-choice assay at 22 ± 1.5°C, A. proletella required significantly more days for development on red cabbage than on broccoli and cauliflower cultivars. A. proletella developed significantly faster on broccoli cultivars Agripa and Chevalier and late cauliflower cultivars Mayfair and Picasso. These results suggest that it is important to minimize the use of broccoli (cultivars Agripa and Chevalier) and late cauliflower (cultivars Mayfair and Picasso) to avoid the risk of further expansion of whitefly populations where these Brassica crops and A. proletella are present.