Whiteflies Impacting Alabama Vegetables

Clint Thompson Alabama, Pests, Top Posts

File photo shows whitefly adults feed on a yellow squash seedling.

This has been the year of the whitefly for vegetable producers in the Southeast. Even as they have been a problem for Georgia vegetable producers, they have also been a nuisance for Alabama farmers.  

Ed Sikora, an Alabama Extension Specialist Professor in Entomology and Plant Pathology at Auburn University, said he’s seen quite a few whiteflies on some of the cucurbit crops like zucchini, yellow squash and pumpkin. The whitefly pressure has increased this year and is impacting locations not used to whitefly damage.

“I don’t work with insects typically, but they seem more common on the cucurbit crops in some of our monitoring plots this year than in past years. Every so often I’ll see the silverleaf damage on squash and so forth,” Sikora said. “This year they seem to be more common than I’ve seen in the last five years on that crop. I saw some last year in the Brewton area. This year I’m seeing them up around, even Auburn. It was heavy down in the Dothan area and in Brewton again.”

What’s most concerning for Alabama vegetable growers are the viruses whiteflies can transmit. They are responsible for transmitting multiple viruses, including cucurbit leaf crumple virus and cucurbit yellow stunting disorder virus. They’re also concerning for vegetable producers in Georgia where whiteflies are before coming to Alabama.

According to the University of Georgia crop loss estimates for fall 2017, the last major infestation period prior to this year, these viruses caused between 30% and 50% crop loss in squash and cucumbers and nearly 80% crop loss in snap beans that year. Vegetables like squash, zucchini, cucumber, cantaloupe and snap beans are highly susceptible to these viruses.

“We’re a little bit concerned because we know that they can transmit some plant viruses. These are occurring in Florida and we assume they are occurring in Alabama as well. We think with more whiteflies in the southern tier of the state that we’re probably seeing more whitefly-transmitted virus problems. That’s something we’re looking into, currently,” Sikora said.