By Clint Thompson
University of Georgia Extension specialists are alerting specialty crop producers that whitefly pressure is on the rise in the Southeast.
Stormy Sparks, University of Georgia (UGA) Cooperative Extension vegetable entomologist, said populations have increased in recent weeks. While the increased activity is normal for this time of year, it still is a concern that growers should be mindful of.
“Whiteflies, I don’t know how broad spread it is, but there have been some local populations that have really jumped (recently),” Sparks said. “We at least made it into August which is good, but we barely made it into August. There’s some locations that are already pretty bad.
“I went to one of Phillip (Roberts’) cotton fields last week to do some stuff, and he said they’ve really jumped up. Ty Torrance sent me a picture of a watermelon leaf where they’ve left a patch. It’s as bad of populations that I’ve ever seen on watermelons. Hopefully, those are isolated incidences.”
Whitefly Impact Can Be Devastating
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. Commercial cultivars that have resistance or tolerance to these pathogens are not available.
While colder temperatures don’t eliminate whiteflies, they do kill many of their wild hosts. They also slow population development in cultivated hosts. Warmer temperatures this winter allowed for larger whitefly populations to overwinter and become mobile earlier.