Tiny Ash Whitefly Laying Siege to Trees and Tempers
Carol Mueller, a gardening enthusiast, has abandoned her hobby because a swirling white cloud of pinhead-sized flies has invaded every corner of her yard.
When the Van Nuys woman must go outside, she wears two bandannas to protect her hair and ears. She waves her hands to keep tiny flies off her body and frequently coughs and puffs air out her nose.
“It’s driving me crazy. They are all over. You wonder if you are breathing them in,” she said, exasperated. “It’s horrifying. When I touch my plants, a cloud rises up in my face.”
Unprecedented Outcry
In the final days of summer, the wrath of the ash whitefly, a pest without enemies, reached an explosive crescendo throughout Southern California, attacking millions of trees and prompting an unprecedented outcry from fly-tormented homeowners, especially in Los Angeles County.
From Van Nuys to Glendora in Los Angeles County and throughout most of San Diego, Orange, Riverside and San Bernardino counties, thousands upon thousands of residents who have long found cool comfort beneath their shade trees are under siege by what is perhaps the most menacing insect to have swept into residential neighborhoods, agricultural officials said.
In San Diego, incidents of the pesky fly wreaking havoc are on the rise.
“We’ve gotten calls from home gardeners, and we’ve seen it on a limited basis during nursery inspections,” said Bill Snodgrass, assistant commissioner of the San Diego County Department of Agriculture. “We’ve experienced some problem, but not nearly on the scale they have in Orange County.”
Snodgrass said that, although the white ash fly does not pose health problems for humans, it can use its suction-like mouth to literally drain the life out of plants. Also, the fly secretes a honey-like residue that weighs down plant leaves and causes them to turn black.
“The fly likes the home gardener most,” Snodgrass said. “But it can create problems for some of our nurseries because we grow a lot of decorative plants here.”
The agriculture department in San Diego is holding a symposium in October on the fly.
Throughout Southern California, Barbecues have been canceled or ruined. Patio furniture has stayed in the garage. Housework has doubled. Many residents have purchased car covers and others keep a bucket of cleaning solution on hand to wipe flies and their sticky droppings off windshields.
Windows stay closed. The insects stick to hair like dandruff. Simply chatting outside with a neighbor is an arm-flailing exercise.
“We’ve never had anything that comes close to matching the citizen-based outcry over this,” said Bob Atkins, Los Angeles County deputy agricultural commissioner for pest prevention.
“They are everywhere. Everywhere!” said Lynn Olson of Glendora, whose front- and back-yard trees are teeming with flies. “Some days I feel like taking an ax to every tree on the block. It’s so frustrating.”
In the last several weeks, Atkins said his office has received up to 200 calls a day from fly-tormented homeowners, forcing officials to install a tape recording. Throughout the county, local city officials say they too are receiving scores of calls.
But there is no good news for callers.
Virtually nothing can stop the flies, entomologists said.
Immune to Sprays
They multiply with lightning speed and have wax-coated wings that are almost immune to pesticide sprays. Residents who do spray find only a few hours respite from the swarms and inadvertently kill insects that can be beneficial to gardens.
Others have turned to drilling holes in their trees and inserting intravenous capsules that leach pesticides in the hope that lethal doses will eventually flow far enough to kill the leaf-sucking flies. Agriculture officials discourage the practice because it is only a temporary fly killer and repeated boring kills trees.
As a last resort, some residents are screwing high-pressure nozzles on their garden hoses and shooting water on their infested trees in an attempt to blast away the pests.
The flies come right back.
“All we can do is tell people to deep water and fertilize their trees to keep them as healthy as possible,” Atkins said. “Unfortunately, that’s not what people want to hear. We are used to quick kills with pesticides.”
The flies attack a wide variety of trees, attaching themselves like white crusts and laying eggs on the undersides of leaves. The flies are slowly sucking the life out of two of the region’s most popular shade trees--ash and ornamental pear.
But they also have an appetite for others, including loquat, pomegranate, Christmas berry, peach and plum. They will also latch onto citrus, but it is not a primary “host tree,” agriculture officials said.
Infested trees will “live under stress” for several years before dying.
The flies, which were first detected in July, 1988, by a Van Nuys vegetable-stand owner, have no natural predators in Southern California, the first North American region to host the fly. The insect is a native of Europe and the Middle East.
Native Lands
By the time the ash whitefly was identified by state entomologists, it had spread throughout Los Angeles County, free from European species of wasps and ladybugs that control the flies in their native lands.
Agriculture officials say the main hope for ash whitefly control is to import the enemy insects. This week, a state entomologist who is in Italy sent back two boxes of the stingerless wasps and ladybugs to UC Riverside, where the insects will be studied.
If the predators can survive and breed in Southern California, feed off the whitefly and not become destructive pests themselves, they could be turned on the ash whitefly as early as next spring, said Thomas Bellows, UC Riverside associate professor of entomology and the whitefly expert supervising the study.
Then, it would take anywhere from two to eight years before residents will detect any kind of population reduction, agriculture officials said.
Early predictions of devasting effects on the state’s $831-million-a-year nursery industry have not come to pass, state agricultural officials and several large growers said. The infestation has not struck the mammoth $634-million citrus industry either.
Healthy Trees
So far, the flies have been mainly attracted to big, healthy trees growing along residential streets and shading the back yards of homeowners.
Infested trees rain droplets of a molasses-like substance--the ultimate insult, fly excrement. When the flies swarm, the excretion floats through the air and settles like sticky dew. Dead, sticky leaves turn moldy and drop onto the sticky ground. The sweet substance attracts ants.
“The floor, the furniture, the mini-blinds, everything is coated with sticky stuff,” said June Amacher, 67, of Glendora. “Leaves stick to the cat, my feet stick to the floor.”
Two houses down from Amacher’s, the Huntington family keeps a bucket of soapy water and a squeegee on the porch to wash their car windows.
“It’s a pain. Every time I drive, I have to clean the windows or else I can’t see,” said Troy Huntington, 17. “And if I walk outside barefoot, it doesn’t feel so good.”
In Whittier, Sylvia Ochoa, 34, said a recent back yard gathering was ruined when flies began swirling around her guests. First, her friends thought the nearby hills were on fire because so much ash was floating in the air.
No, Ochoa told them, it was the ash whitefly.
Stuck to Hair
“Then for some reason the flies were attracted to the ladies with hair spray,” Ochoa said. “It was kind of funny, they all left with white flies stuck to their hair.”
About 10 miles south, Lorean Wirt of Cerritos was dumbfounded several weeks ago when she found that her gold car parked beneath the ornamental pear tree was covered with a white veil. When she brushed the vehicle, flies swooshed up toward her.
“It was disgusting,” the 30-year-old woman said.
Now, she dreads seeing neighbors on her way out to her fly-swathed car.
“I don’t even want to open my mouth and say hello. I just nod my head, wave and get in the car as fast as I can. It’s the safest thing to do,” she said.
Back in Van Nuys, the flies were so thick on Enfield Avenue that resident Tom Spicklemire is reluctant to fire up the barbecue and grill himself a steak.
“The second you take the meat off the grill, flies start landing on it,” he said. “It’s miserable.”
Carol Mueller across the street echoed the wishes of many who have found themselves under ash whitefly siege.
“I’m hoping for a cold, wet winter,” she said. “Maybe that will take care of the little devils.”
