Whitefly Populations on the Rise in Field Production
The mild winter coupled with the hot and dry weather conditions in the southeast U.S. have resulted in high populations of whitefly this summer. Vegetable and cotton producers in Georgia, Alabama, and Florida are reporting higher than normal populations earlier than normal.
Historically, whitefly populations are localized in the Southeast with population surges normally observed in August. This year, whitefly treatments in vegetable crops began with spring crops, which is highly unusual. The first identification in cotton came in June, over a month ahead of normal. Therefore, greenhouse and nursery producers in the South should be on high alert for early whitefly infestations.
This is a good time to remind folks in the green industry about the importance of biotyping your whitefly population, especially if pesticide management has failed. Biotype Q is the one to be feared, because it is resistant to many classes of insecticides, such as insect growth regulators, pyrethroids, and some neonicotinoids. However, there are control options for it. Q is also twice as likely to carry plant viruses than other biotypes.
So far this year, Q has been positively identified in four states, including California (hibiscus, lantana, gerber daisy), Oregon (poinsettia), New York (poinsettia), and Texas (lantana). Q was also detected in Quebec, Canada on greenhouse tomato.
The Floriculture and Nursery Research Initiative (FNRI), administered by USDA-ARS in collaboration with AmericanHort, HRI, and SAF, provides funding to cover the costs of biotyping. Results are anonymous. For more information, please visit the Mid-Florida Research & Extension Center’s Bemesia website.