Worry Spreading In Florida Over Exotic Whitefly

Worry Spreading In Florida Over Exotic Whitefly

Closeup of Q-biotype or B-biotype whitefly

Is this a Q-biotype or B-biotype whitefly? The two pests look identical, according to researchers.
Photo courtesy of UF/IFAS

The recent discovery of a notorious whitefly in Palm Beach County has Florida vegetable and ornamental plant growers on alert and researchers on edge.

The Q-biotype whitefly (aka, Mediterranean whitefly, Bemisia tabaci) is now being seen outside greenhouses and nurseries and poses a threat to ornamental plants and agricultural crops.

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UF/IFAS Plant Pathology Professor Jane Polston predicts the Q-biotype whitefly will likely cause problems for growers. “This Q-biotype is a pest that damages crops and resists many of the insecticides that are effective on the B-biotype, the whitefly that is common in many ornamental and vegetable crops. And like other whiteflies, it is capable of transmitting viruses from one plant to another.”

But because the Q-biotype whitefly feeds for longer periods on some plants, it has a greater chance of acquiring a plant virus, Polston said. The more time a whitefly spends feeding on a plant, the more likely it is to acquire a virus from an infected plant. Only a few studies have been conducted on the host plants that Q and B feed on, but those few studies indicate that Q and B do have different preferences, she said.

Because these whitefly species feed differently, vegetable and ornamental crop growers may see different viruses in their crops, as well as how many plants become infected each season, Polston said.

“And because it’s harder to manage with pesticides, we may see higher populations of this new whitefly, and that can mean high numbers of virus-infected plants,” she added.

Viruses may show up in plants that were not infected before, Polston said. Scientists and Extension faculty also should be prepared to see changes in the percentage of infected plants on farms, she said.

According to a 2013 paper that Polston co-wrote, the Q-biotype whitefly can transmit many different plant viruses, such as tomato yellow leaf curl virus, squash vein yellowing virus, tomato infectious chlorosis virus, cowpea mild mottle virus, and many others.

When the whitefly was reported this spring, it marked the first time the Q-biotype of B. tabaci had been found outside a greenhouse or nursery in the U.S. since it was found on an ornamental plant in a greenhouse in 2004-2005, said Lance Osborne, a UF/IFAS entomology professor.

Researchers with UF/IFAS are working with the USDA-Agricultural Research Service and the Florida Department of Agriculture and Consumer Services (FDACS) to manage the whitefly.

The agenda for the 2016 Florida Ag Expo is slated to feature an educational session discussing the status of the Q-biotype whitefly in Florida.

Nurseries that suspect whitefly infestations should contact the FDACS Division of Plant Industry at 1-888-397-1517.