By Clint Thompson
Whitefly populations remain low across the Southeast. Fall vegetable growers have the Christmas freeze event last December to thank for that, believes Stormy Sparks, University of Georgia (UGA) Extension vegetable entomologist.
“I think that’s a lot of it. We’ve had some wet weather, too, but I think that’s a lot of it. It knocked them way back. We just didn’t have a lot coming out of winter,” Sparks said. “We’ve had a couple of reports of some whiteflies in some stuff but nothing severe. There was some type of cucurbit field, but they were getting ready to take it out, but it had populations in it. I heard of one cotton field that they were building up in, but that’s still pretty light for this time of year.
“We haven’t seen a whole lot, no. It’s still been a fairly light year for whiteflies. But if we turn hot and dry it could change.”
Whiteflies migrate from winter vegetables to spring vegetables to agronomic crops, like cotton, to fall vegetables and back to winter vegetables. The buildup of whiteflies is concerning since they can cause feeding injury issues in vegetables and transmit multiple viruses. These include cucurbit leaf crumple virus, cucurbit yellow stunting disorder virus, cucurbit chlorotic yellow virus, squash vein yellowing virus and tomato yellow leaf curl virus.
Vegetables like squash, zucchini, cucumber, cantaloupe and snap beans are highly susceptible to these viruses. Southeast specialty crop farmers grow cole crops, like broccoli, kale and cabbage, from September through May. Cucurbits are produced in the summer, and cotton is grown in the early fall. All of these crops serve as host plants for whitefly populations.
“If you’ve got low populations out there, they can build pretty rapidly under hot and dry conditions. Typically, in really bad years, they’ll be treating cotton for whiteflies this time of year. As far as I know, if they’re treating, it’s very minimal. At the very least, it doesn’t look like it’s going to be a bad year. But I don’t think we’ll get by without them either,” Sparks said.