The rugose spiraling whitefly is creeping up Florida and now infesting pools in the central part of the state.
First appearing in Florida in 2009, the species attaches to trees with coconut palms, often planted in the proximity of pools. The flies deposit a black goo on decks and furniture, and leave a film on pools that can neutralize chlorine.
By last summer, the pest’s range reached into Palm Beach County, where service technicians were forced to add chlorine daily to some pools to maintain residuals. Now the rugose spiraling whitefly has traveled more than 100 miles north of there. It’s infesting the state from Cape Canaveral to just south of Tampa and is particularly prevalent in the coastal areas.
That includes Longboat Key, a resort area on the Gulf of Mexico. Todd Starner, a pool tech based in Bradenton, has seen the whitefly in two pools he services there. “When you start to get whitefly, it’ll look like you have sawdust in the skimmer, he said. “I’ve been putting the pools on enzymes.”
Starner said those chemicals break down the sugary substance of the secretion and allow it to filter out. That helps him get the free chlorine residual up to 0.5 or 1.0 ppm so the pools stay clear. The next step is to have the homeowner call a pest control company and treat the trees surrounding the pool. It’s not enough just to treat one tree, though, because the whiteflies often will just move to an untreated tree.
Part of the problem with whiteflies is that as the pest increases its range, it hits areas where pool techs are unaware of what they can do. “It’s something new. I don’t have much experience with it,” said Mark Dean, service and warranty manager at Holiday Pools of West Florida in Sarasota. Dean said he poured 30 gallons of chlorine into a cloudy pool at a foreclosed home one day, and three days later, the pool had no chlorine level. He repeated the process, this time adding granular chlorine to the liquid. A couple of days later, he had no chlorine level, but a TDS level of 2,000. Now, the owner of the home is having Dean drain the pool and start fresh.
Currently, the main defense against the whitefly is chemicals, ranging from store-brand dish soap to pesticides. But experts are working on other approaches. “We’re trying to buy ourselves some time to look at biological control, using predators, parasites and pathogens to manage the whiteflies,” said Lance Osborne, interim director of the Mid-Florida Research & Education Center in Apopka. The center is having some success using beetles and small wasps to control the whiteflies.
“We took a whitefly infestation that was just getting started at a hotel in Palm Beach and released parasites a year ago. I went back and we could find hardly any rugose spiraling whitefly on the plants. For one whole year, we protected those plants without even using soap and water,” Osborne said. He emphasized that no new organisms are being introduced to the state to combat the whitefly. “We’re just trying to harness what’s already out there,” he said.
He also cautioned homeowners against using hoses to remove whiteflies from overhanging tree limbs unless they can ensure that the flies won’t drop into the pool. “Some of these flies have a hydrophobic covering, so that’s why you use a little soap or oil to break the surface tension,” he said. “We’re getting good control of the whiteflies in the greenhouse just using Publix [a regional supermarket chain] dish soap.”
Pools aren’t the only victims of whiteflies. Tom Sanger, pool service manager at LaPensee Plumbing and Pools in Bradenton Beach, said that he’s seen the pest do its work on a couple of pools with chlorine generators for which he’s responsible. But they’ve hit even closer to home. “We’ve also had the whiteflies on the trees at our shop and they’ve almost ruined a couple of vehicles’ paint,” he said. “They’re nasty little suckers, that’s for sure.”