Photo courtesy of PINELLAS COUNTY EXTENSION SERVICE
Residents are reporting whitefly problems.
BELLEAIR SHORE – A pest labeled as “extremely damaging” to plants and capable of causing “cataclysmic effects in the landscape” has been reported in the community.
Mayor John Robertson said at the Nov. 20 town commission meeting that some residents had reported swarms of whiteflies attacking their palm trees.
According to a bulletin issued by the Pinellas County Extension Service in July headlined “Whitefly Invasion,” the pests “can reach very high populations and can be extremely damaging.”
Extension Agent Jane Morse said in the article, “Whiteflies can seriously injure plants by sucking nutrients from the plant causing wilting, yellowing, stunting, leaf drop, or even death.”
The flies feed on a broad range of plants, including palms, woody ornamentals and fruits, she said.
Their presence is easy to spot, Morse said, from the white, waxy, web-like substance they leave on the plant leaves when laying their eggs. Also evident is the “honeydew,” a sticky substance they produce which causes the growth of a mold that looks like black soot. Besides damaging plants, the substance also can drop into pools, “creating a mess,” Morse said.
Morse told the Belleair Bee that the whiteflies were first seen in Miami-Dade County in 2009 and have since migrated to the west coast of Florida, reaching Pinellas County in recent months. These whiteflies are large, about three times larger than other whiteflies occurring in the United States, she said.
They are an exotic species, likely introduced in South Florida on shipments arriving from Asia, Morse said.
Whitefly infestation was noticed this fall by Belleair Shore resident Deborah Roseman, who co-hosts a weekly radio program called Garden Talk on WTIS AM 1110. She pointed out the evidence of the insects’ presence during a recent interview at her home on Gulf Boulevard.
“My husband Ron and I noticed circular cobwebs and sooty material on the fronds of our coconut palms. We took a sample to the county extension service and were told that it was a telltale sign of whiteflies,” she said.
Roseman said half a dozen properties in Belleair Shore have been affected so far. She is concerned others may have whitefly infestation, but not be aware of it. In addition to palm trees, whiteflies can attack other tropical foliage, such as Bird of Paradise, crotons and live oak.
“They’ll hit anything woody,” said Roseman.
Indian Rocks Beach resident Donna Valery said her ficus trees have had whiteflies “real bad” since last year. Other residents have reported similar infestations, mostly targeting ficus, she said. Valery said a landscaping service charged more than $1,000 for a treatment that was only temporarily successful.
Indian Rocks Beach Public Works supervisor Randy Schwab said, “The whiteflies are in every ficus tree here, and in Largo and Indian Shores too.”
No whiteflies have been reported in Belleair Beach so far, according to Community Services Director Allen Godfrey. Godfrey speculated the insects could have come to Belleair Shore with the exotic palms that have been a part of the landscaping of new home sites there.
Morse said that is entirely possible. But however they have arrived, the affected residents need to take appropriate steps to eliminate the whiteflies and halt their spread.
Pest control must be done with care, Morse said, to avoid destroying the whiteflies’ natural enemies, called parasitoids, which eat their larvae. Insecticides often kill both the good and the bad insects, especially when sprayed, she said.
“The [whiteflies’] natural enemies do the bulk of pest control, and you don’t want to kill them,” Morse warned.
She recommends treating small whitefly infiltrations first by washing the plants off with water. This can be done with a hose to reach tall trees.
Use of a horticultural oil to spray on foliage, and insecticidal soap also can be helpful in controlling whiteflies. These are available at nurseries and garden centers. The soaps and oils “do work really well,” Morse said. A hose or sprayer can be used to apply them. She recommends a drench, starting at the base of the tree.
While large or persistent whitefly infestations may require the use of insecticides, their misuse or overuse may cause other problems such as insecticide resistance, secondary pest problems, environmental contamination, and destruction of beneficial insects, Morse said.
Eliminating the pests and stopping the spread is critical to maintaining the health of our diverse and beautiful palm species, she stressed.
Roseman recommends bagging all affected leaves and fronds, rather than leaving them on the curb, as the whitefly infestation is spread through the air.