BRASSICA CARINATA: NEW REPRODUCTIVE HOST PLANT OF BEMISIA TABACI (HEMIPTERA: ALEYRODIDAE)

A laboratory experiment was conducted on two potential reproductive host plant species of the whitefly Bemisia tabaci (Gennadius). The two plant species, Brassica carinata A. Braun (carinata or Ethiopian mustard) and Myrica cerifera L. (southern wax myrtle), were considered for study as potential overwintering host species for B. tabaci because of their presence with green foliage in the southeastern United States agricultural community from the fall through spring season. The MiddleEast-Asia Minor 1 of the cryptic whitefly species group of B. tabaci survives the mild winters in the southeastern United States. In this study, B. carinata was demonstrated to be a favorable host plant for B. tabaci. Based on a no-choice experiment, oviposition, egg hatch, and survival to the adult stage were similar for whiteflies on B. carinata as compared with collard (B. oleracea var. acephala de Condolle), a known favorable host for B. tabaci. However, results from a dual choice experiment indicated that the whiteflies preferred B. carinata to B. oleracea for feeding and oviposition. Conversely, although southern wax myrtle served as an ovipositional host, the ovipositional performance of B. tabaci in a no-choice assay was over eight-fold less than on B. carinata, and nymphal survival was not successful beyond the second instar on southern wax myrtle in a laboratory experiment. However, a few nymphs survived to the fourth instar on intact plants of southern wax myrtle in the landscape. The results of this study have implications on whitefly population dynamics. Winter populations of B. tabaci are suppressed in the field, but plant species, such as carinata or collard, that are present during the mild winter may help support a buildup of whiteflies during the spring.