The Heat Is On

An aggressive species of fire ant, previously contained to nurseries and orchards in California, has colonized a 20-mile swath of backyards, parks and other residential areas of suburban Orange County and appears to be spreading, state agricultural officials said Thursday.

The red imported fire ant, which can attack en masse and inflict painful bites, has plagued southern states in the Gulf region for decades. California has kept it under control through regulation and treatment at nurseries and orchards.

“This is the first instance of infestation in a residential area in California that we know of,” said David Asakawa, head of a 25-member detection team for the California Department of Food and Agriculture.

If not checked, the fire ant “could eventually spread to all areas of the state, except for the driest deserts and coldest mountains,” he said.

The manicured lawns, golf courses and green belts of the county are ideal breeding grounds for the ants, which thrive in warm, irrigated turf, scientists said.

More than 70 mounds have been flagged in Orange County over the last two weeks. Up to 40 are in a small park in front of the Trabuco Highlands apartment complex in the Robinson Ranch planned community.

Isolated mounds, some as small as the size of a teacup, have been found as far south as the end of Oso Parkway, east to the communities of Trabuco and Dove Canyon, north to O’Neill Park and near St. Michael’s Monastery and west to near the Portola Hills toll plaza on Route 241.

The infestation was discovered last week after the Nevada Department of Agriculture informed California officials it had intercepted nursery plants being shipped from TY Nursery in South County.

That nursery and one next to it probably had no idea they had a fire ant problem, Asakawa said. The nurseries now are under quarantine. That means every recent plant shipment is being tracked and examined, and thousands of plants due to be sold are being drenched with pesticides and inspected before they can be shipped.

None of the ants have been found in Los Angeles County. However, county inspectors there are monitoring six nurseries that bought supplies from one of the infected Orange County nurseries. The nurseries under watch are concentrated in two areas, around Pico Rivera and Torrance.

Fire ants have been found at nurseries and orchards in the Central Valley and in Santa Barbara County. Three Central Valley orchards are under quarantine.

A commission of national and international experts is being assembled, state and county officials said, and will convene here within 10 days to determine possible methods of controlling the problem.

The ants, distinguished by a bright red head and middle portion, will “erupt in a volcanic stream” if their burrows are disturbed, such as when someone steps on or mows over a mound, said Nick Nesson, entomologist for the Orange County Agricultural Commission.

In the South, they have destroyed farm machinery, livestock and vegetation--and cost states hundreds of millions of dollars in eradication efforts. In infested urban and suburban areas, lying in the backyard or having a picnic has become a thing of the past, experts there said.

The entire stream can crawl rapidly over skin or any other surface in its way, inflicting painful, lasting bites. Usually, the bites cause a dull, burning sensation that lasts for a few hours, followed within 24 hours by a white raised bump that will become infected if scratched. The bump goes away in a week or two.

Single Bite Can Cause Welts

In rare instances, a single bite can cause painful welts, even death, said Michael Merchant, an urban fire ant specialist with Texas A&M;’s agricultural extension program. According to studies, an estimated one in 10,000 people will suffer a violent allergic reaction that can lead to death, he said.

One Coto de Caza man, Steven Dickinson, 42, who lives near the most heavily infested area in Orange County, passed out after being bitten by two ants in his backyard Oct. 5.

“I was hammering a fertilizer stake into the ground next to a tree, and an ant bit me on the hand. I brushed it off, and another one bit me on the other hand.”

Within 10 minutes, he said, “I was covered with red welts from the bottom of my feet to the top of my head.”

Bewildered doctors at Mission Hospital Regional Medical Center assured him it could not have been the ants that caused the reaction. By morning, the welts were gone and he was fine.

Two days later, he said, the doctor called back and told him he probably was right about the ants. Dickinson said he now has a prescription for epinephrine packed in his golf bag, his car and house. But his young sons, who at first tried to attack the ants with their plastic swords, now are scared to go in the backyard, he said.

“I always thought it was the rattlesnakes I had to worry about,” Dickinson said. “Turns out, it’s the ants.”

Normal ant sprays and traps will not wipe out the fire ant, which often has multiple queens burrowed deep under sidewalks, fire hydrants or electrical boxes, where they have protection and access to water. State officials want residents to hold off trying to destroy mounds themselves until experts devise an eradication plan.

California and Texas experts said the ants wreak havoc with ecosystems by feeding on small rodents, lizards and ground-nesting birds.

When a haying machine makes contact with a hardened mound, “it’s like hitting a big rock,” Merchant said. Texas, he said, has suffered “ecological devastation” as a result of the invasive fire ant.

The ants caused $100 million in damages in Texas last year, he said, and the state spent $2.5 million trying to control the insects.

“We don’t talk about eradication in Texas anymore, we all just talk about controlling,” he said. “These things are so prolific and so adaptable.’

Former Texas resident Warren Smith, now living in Robinson Ranch, said: “It’s scary as hell. I never thought I’d have to deal with these things again.”

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

Red-Headed Wave

Red imported fire ants, a particularly aggressive pest, have appeared in force in South County, colonizing a 20-mile-wide section:

Red Imported Fire Ant

Size: 1/16- to 1/4-inch long (largest workers can be two to three times larger than the smallest)

Distinguishing marks: Bright red head and middle body

Home: South America

How they arrived: Probably in the soil used as ships’ ballast; they entered through the port of Mobile, Ala., between 1935-40

Residence: Mounds can stand up to 18 inches tall and 6 feet below ground, with a 2-foot diameter

Colony population: Up to 300,000

Fecundity: May be up to 60 queens in a colony, each capable of producing 1,500 eggs per day in optimal food and weather conditions

Behavior: They emerge quickly and aggressively when mounds are disturbed.

Sting cycle: The hot, painful sting usually leaves a white pustule within 24 hours.

Sting treatment: Watch area for excessive swelling, itching or redness; keep stings clean and intact to avoid secondary infection. Also watch for signs of allergic reaction, including shortness of breath, thickening of the tongue, sweating and the like. If you have what could be an allergic reaction, seek medical attention.

Sting lethality: In rare instances, such as allergic reactions, sting may prove fatal.

Fighting them: Experts will convene here Dec. 1 to help determine ways to fight the ants. Various kinds of chemicals/baits are used in other states, such as Texas. If you must fight them sooner, consult a pest control specialist or nursery.

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Nonchemical Combat

Scald Them

Pour two to three gallons of boiling water on the mound. Yields about a 60% kill rate.

Drown Them

Cover the handle of a shovel and inside of a bucket with talcum powder. Shovel the ants into the bucket (the talcum will keep them from climbing up the shovel handle toward you and from climbing out of the bucket). Once they are in the bucket, add water until it covers the dirt and stir in one-quarter cup of dishwashing liquid. Soap will break the water surface tension and the ants will drown (without the soap in the mixture, they will float).

Sources: Orange County Agricultural Commissioner; Texas Agricultural Extension Service, Texas A&M; University. Researched by LOIS HOOKER and TOM REINKEN