Location: Vegetable ResearchTitle: Brassica carinata: new reproductive host plant of Bemisia tabaci (Hemiptera: Aleyrodidae)
|OLANIYI, OMOTOLA - Orise Fellow|
|ANDREASON, SHARON - Orise Fellow|
|Strickland, Timothy - Tim|
Submitted to: Entomological News
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/2020
Publication Date: N/A
Interpretive Summary: Carinata (Brassica carinata; also called Ethiopian mustard) is expanding as a marketable cover crop or seed crop in the southeastern U.S. The whitefly Bemisia tabaci is a major agricultural pest and it can survive year-round in regions with mild winters, such as the southeastern United States. A study was conducted to explore the possibility that carinata or the southern wax myrtle (which is common in the southeastern U.S.) could serve as host plants for this whitefly; if so, this pest may be able to survive the mild winter on these plants and move to vegetable and other crops in the spring. We found that carinata is a good reproductive host plant for this whitefly, but the whitefly did not complete its survival on wax myrtle. The results of this study help researchers and pest management specialists in understanding the population dynamics of whiteflies and associated viruses in the agricultural landscape.
Technical Abstract: 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 Middle-East-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 good 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 good host for this whitefly. 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 five-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.