Whiteflies are in high numbers and spreading to areas in Georgia not prone to whitefly infestations every year. That is tough news for the state’s cotton producers with harvest season just around the corner.
“They’ve really built high numbers in areas prone to get whiteflies. In those areas we have high populations. Growers are actively treating,” University of Georgia Cooperative Extension entomologist Phillip Roberts said. “The question is, ‘How far are these economic infestations going to spread?’ Right now, they’re spreading.
“It doesn’t quite look like 2017. People remember that year because they got across all of Georgia that year. But this is going to be a tough year. They are moving into areas where (farmers) typically don’t deal with them.”
Roberts stated in late July that whitefly populations had exploded from moderate to really high. It was due in large part to high temperatures and lack of rainfall. Those conditions continued into early August and contributed to whiteflies spreading across cotton fields and cucurbit crops.
Whiteflies can reduce cotton yields and affect cotton quality if left uncontrolled. They are sucking insects that feed similarly to aphids. When whiteflies feed on a plant, they excrete a sugary substance called “honeydew,” which serves as a host for the sooty mold fungus. The accumulation of honeydew and sooty mold leads to quality problems on open cotton bolls.
Let Beneficial Insects Help
How farmers manage stink bug populations can also influence whitefly numbers. Roberts said last week that growers do not need to apply insecticides if they do not have to with regards to stink bug treatment. Any insecticide used to kill stink bugs will kill beneficial insects, which could potentially help in controlling whiteflies.
“Beneficial insects are so important when we’re trying to manage whiteflies because treatments for whiteflies are very expensive. We need to try to let Mother Nature help us all she can,” Roberts said.
Whiteflies are a greater problem this year due in large part to the mild winter. While colder temperatures do not eliminate whiteflies, they do kill off many of their wild hosts and slow population development in cultivated hosts. Warmer temperatures allowed for larger whitefly populations to overwinter and become mobile earlier this summer.