By Clint Thompson
Whitefly populations are on the rise in South Georgia. While their numbers are not overwhelming, they have increased in recent weeks, says Stormy Sparks, University of Georgia Cooperative Extension vegetable specialist.
“Whiteflies have increased over the last week or so, not dramatically, but they’ve obviously increased. Phillip (Roberts) tells me in cotton there’s not high numbers, but they’re fairly widespread. If it goes hot and dry, we could build up fairly quickly,” Sparks said. “If this tropical system (Fred) comes through and drops rain everywhere, it could actually do a lot of good as far as keeping them from building. We’ll just have to wait and see.”
The potential buildup of whiteflies is concerning since growers are about to plant their fall crops. Whiteflies can cause feeding injury issues in vegetables and transmit two viruses: cucurbit leaf crumple virus and cucurbit yellow stunting disorder virus. Vegetables like squash, zucchini, cucumber, cantaloupe and snap beans are highly susceptible to these viruses.
Fortunately, at this point in the summer, infestations remain low compared to previous years.
“In our squash trials, we were less than 10 per leaf last week. We’re about 30 per leaf this week. This time last year, we were 100 to 150 per leaf. We’re still low populations relatively,” Sparks said.
Whiteflies migrate from winter vegetables to spring vegetables to agronomic crops, like cotton, to fall vegetables and back to winter vegetables.