By Antigone Barton
While the ficus whitefly continues to challenge landscapers seeking to preserve privacy hedges, a new pest has arrived with its own set of challenges.
Not the least of those challenges is confusion, as it shares a last name with its exotic-plant eating predecessor.
The spiraling whitefly, however, is not to be mistaken for its picky predecessor, as owners of native plants up the coast of Palm Beach County are learning.
“Some of the worst damage we see is on the gumbo limbos,” says Laura Sanagorski, environmental horticulture agent at the Palm Beach County Cooperative Extension Service. “It’s probably their favorite food on our landscape menu.”
But she adds, unlike the ficus whitefly, the spiraling whitefly is open to variety.
“It loves our coconut palms, our adonidia palms,” she continues. The list goes on: black olive, sea grapes, live oak.
And, she adds, it’s not picky where it lays its eggs, either. The extension service continues to discover new hosts for the latest pest.
The insect is about three times the size of the ficus-eating whitefly, “you can make out its parts, see the wings,” Sanagorski says.
It has moved up the coast over the last two years, since its arrival, probably from Central America.
With no natural predators in Florida, and an ability to produce from 50 to 400 offspring in their short lives, they have made their presence felt from Boca Raton to Jupiter, according to Brent O’Keefe, route manager for O’Hara Pest Control.
In addition to the eyesore of bare branches, they leave the sticky substance of their “honeydew” excretions behind on patios, pools and furniture, which then fosters the growth of sooty mold.
And, says John Schiller, general manager of Environmental Pest Control, they have had a bigger impact on the coast than inland.
“I think it’s because it’s where the candy store is,” he said.
The good news is that when they move on, the damage is not lasting.
“Typically, you won’t lose the tree to it. Once the leaves are gone, they will leave the tree alone,” Sanagorski says. “The tree will push out new growth.”
They are likely to return without efforts to control them, experts agree. The means of control depends on the plant and degree of infestation, with horticultural oils and soaps effective against smaller infestations, Sanagorski says.
Imported beetles have proven to be predators, but are unlikely to be available in sufficient numbers to control the insect here, according to Schiller.
For that reason, they are likely here to stay.
“There’s no eradicating them,” Schiller says, “just controlling them.”
Then, of course, Sanagorski says, new pests, drawn to the year-round growing season of a subtropical climate, are sure to arrive.
“There will be others,” she says, “and hopefully we’ll have this under control before too
Recognizing whitefly invasion
The spiraling whitefly is larger and less picky than the ficus whitefly. You will see it on a wide range of foliage, including:
• Gumbo limbo
• Black olive
• Copperleaf, cocoplum and wax myrtle shrubs
And new foliage susceptible to spiraling whitefly attack continue to be noted.
• White spirals on leaves
• Buildup of white waxy substance on underside of leaves
• Black sooty mold that grows on whitefly excrement
What to do
• Diversify: The more diverse your landscape, the less susceptible it will be to pests, diseases, even storm damage
• Monitor: Be familiar with your landscape and with the signs of whitefly damage, respond quickly.
• Wash plants where whitefly is spotted with a strong stream of water.
• Use a systemic product to drench the soil surrounding larger plants (preferred).
• You may also spray a topical product directly on leaves to tackle active whitefly.
• Repeat: A one-time treatment may be a temporary fix. Be familiar with the product you use, follow label for safest, most effective use.
• Do not use pesticides on fruit-bearing trees unless product label specifies it is appropriate for that use.
Sources: Palm Beach County Whitefly Task Force (www.pbcgov.com/coextension/horticulture/whitefly), University of Florida Institute of Food and Agricultural Studies