South Georgia-grown pumpkin crops are at risk this Halloween season and it’s all because of a small bug described as “sap-sucking insects.” They’re called Whiteflies, and they thrive in high temperatures so the recent heat has meant rapidly rising whitefly populations.
When uncontrolled, whiteflies can reduce crop yields and affect crop quality. Whiteflies are described as sucking insects that feed similarly to aphids. When they feed on a plant, they excrete a sugary substance called “honeydew,” which serves as a host for diseases.
“I work with cucurbits [plants in the gourd family] and I’ve seen an extremely high increase in whitefly population last year, and this year as well,” said Dr. David Riley, a professor of entomology at the University of Georgia’s Tifton campus. “They’re becoming a statewide concern, particularly in the southern part of Georgia.”
Whiteflies are tropical insects that like heat, making them difficult to control in Georgia. Winter temperatures normally kill off the wild plant hosts, which slows whitefly population development.
This year, milder winter temperatures allowed the pest to develop early in the season and increase its population numbers. “Global warming is affecting the whitefly population,” explained Riley. “Warmer winters mean more whiteflies.”
“Global warming is affecting the whitefly population. Warmer winters mean more whiteflies,” said Riley.
Last year, whiteflies wiped out the crop of Orange Bulldog Pumpkins, a strain of pumpkins developed by the University of Georgia to be virus resistant. This event left no seed available in 2017 for hopeful pumpkin growers to purchase.
Dr. George Boyhan, the lead researcher on the project, explained that the whiteflies were so bad that they had to completely wipe out the last year’s crop and put a new floor in the greenhouse where the pumpkins had been growing.
“It was a huge issue for us last year,” Boyhan said. “It seems to be under control this year. We really hope to continue selling seed, we got good feedback from farmers [able to grow the pumpkins last year].”
Georgia climate is not well-suited for pumpkin growing, a process that succeeds best in cool nights and with lots of rain, according to a publication by the UGA extension office.
Most Georgia pumpkin patches have their pumpkins imported from cooler states up north. Boyhan hopes to change this by developing strains of pumpkins like the Orange Bulldog Pumpkin that can survive the Georgia summers.
Pumpkins aren’t the only crop affected by the rising whitefly population; Georgia cotton has suffered from whitefly infestations as well. County extension agents have been warning local farmers to try to catch these pests early before they become a problem.
Riley agrees that early detection and avoidance is key to managing the pests. “The biggest issue with whiteflies is that they are highly resistant to insecticides,” said Riley.
Pumpkins that are ready to be harvested in October are primarily developing during the hottest part of the year, leading to high susceptibility to diseases and pests like whiteflies.
“I’ve always said that, if it were possible, I’d grow my pumpkins early and then store them through the summer,” said Riley. “It’s a hard thing to do.”
– Nicole Adamson