UGA Vegetable Entomologist: Potential Explosion of Whiteflies This Fall Never Occurred

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Whitefly adults feed on a yellow squash seedling.

Whiteflies were projected to have a widespread, devastating impact on fall vegetable crops in Georgia. But according to University of Georgia vegetable entomologist Stormy Sparks, that never happened.

“We were setting up for an explosion of whiteflies in the fall and it never really occurred,” Sparks said. “I’m pleasantly surprised it wasn’t a lot worse than it was. In the summer, we were set up to be ugly, ugly.”

Greater Problem This Year

Whiteflies were a greater problem this year due in large part to a mild winter last year. They were widespread and posed a similar risk to the fall vegetable production that Georgia producers experienced in 2017. Thankfully, it never materialized.

“It didn’t get nearly as bad as I thought it was going to get. I think cotton growers deserve a pat on the back. I think they did a much better job of managing it than they have in the past because they expected it,” Sparks said. “I was really expecting virus to wipe out some of the crops and it didn’t happen. I was really pleased with that. I think a lot of it is just the area wide management of whiteflies.”

Impending La Nina

Whitefly management continues to be a crucial component of vegetable production with the expectation of a La Nina weather pattern this winter. A La Nina is expected to bring warmer temperatures and drier conditions throughout the winter and into early spring. This could allow for more overwintering of whiteflies if the colder temperatures do not kill off their host plants.

“We want cold weather to kill the host plants. We don’t ever get cold enough to kill whiteflies. It takes a lot of cold for a long period to kill a whitefly. But what we (want) is to kill the host plants, which all it really takes is a frost for a lot of them,” Sparks said.

“When we get rid of cucurbits, that gets rid of a lot of our major host crops. Then it’s management of whiteflies in those cole crops that is very important during the winter. The generation time really lengthens so you don’t tend to have a lot of buildup, but you can carry them through, the warmer it is and the less we manage them.”