Ant invaders making Texans crazy
AUSTIN — There’s a hitchhiker traveling across Texas, and if it hasn’t yet crawled into your computer, plugged up the electrical pump on your well or just chewed through your serenity, stand by.
Seven Texas counties have reported crazy ants this fall, adding to the 28 reported last year, and Robert Puckett, a Texas A&M entomology professor, thinks there are probably others that don’t yet realize they’re infested.
“They’re a beast,” said Puckett, who is part of the team at A&M’s Center for Urban and Structural Entomology. “I always tell people we’re going to take care of it, but they’re going to be trouble for a long time.”
Crazy ants — also called the Rasberry crazy ant or tawny crazy ants — like enclosed spaces, have hundreds of queens in a colony and can shut down productions lines by short-circuiting electronics. They can even drive out fire ants, surviving the competition’s stings by detoxifying its venom.
Spotted by Pearland, Texas, exterminator Tom Rasberry around Houston in 2002, crazy ants are now on the march, prompting scientists from here to Florida to look for a silver bullet to stop the economic and environmental threats posed by the flea-size pests.
“You may have 10,000 colonies on an acre,” Rasberry said. “When you get 15 billion to 18 billion (ants) to an acre, there’s nothing that’s actually safe.”
Though he does’t have a doctorate, Rasberry has logged thousands of hours studying crazy ants, so called for their random, zigzagging gait.
About three years ago, he had a contract to treat 80 acres at the Johnson Space Center, hitting the crazy ants there with a commercial pesticide.
“I know for a fact that they’re starting to pop back up in the Space Center,” said Rasberry, who’s no longer the pest-control contractor there. “Next year they’re probably going to have a problem.”
It’s not just Houston that will have a problem.
Crazy ants are now in Austin, and the only limits on their march seem to be cold temperatures and dry climates.
Nobody knows exactly how the reddish-brown ants first made the trip from central South America, but they’re now expanding across the warm, moist Gulf Coast states.
When moved by people, they travel in potted plants, landscaping material, old plywood and even recreational vehicles.
Ed LeBrun, a research scientist at the University of Texas’ Brackenridge Field Lab in Austin, said that while they only spread about 600 feet in any direction per year, crazy ants can move into any kind of cavity. That makes ideal targets of warm, tight places such as televisions or electrical boxes connected to home air conditioners.
“There’s no evidence that the electricity itself was attracting them,” he said. “It seems to be the box.”
Given the fact that queens lay two to four eggs per hour, day in and out, it’s little wonder that crazy ants and their giant colonies are spreading.
Huntsville exterminator Charissa Gibson said she’s seen crazy ants all around the Walker County seat over the past two or three years.
Unlike fire ants, they don’t sting, instead inflicting a bite that fades quickly and doesn’t cause allergic reactions in humans.
Gibson considers crazy ants more nuisance than threat, though there’s exterminators can do except knock back populations temporarily.
Yet, experts say, the threat to agriculture and wildlife is very real.
Texas A&M’s webpage devoted to the ant, which has the Latin name Nylanderia fulva, reports that crazy ants have been a “serious pest” in rural and urban parts of the country of Columbia.
There they’ve displaced other ants and killed off small animals, such as chickens, from asphyxia. The ants have attacked larger livestock around the eyes, nose and hooves.
Rasberry recalled how imported fire ants once vanquished the big, native harvester ants that were a food source for the now-rare horny toad. He fears that crazy ants could cause even more serious ecological problems — killing off honey bees, for instance.
“That’s what we get a big percentage of our pollination from,” he said. “My concern is how much damage they do to an ecosystem.”
In a 2013 article, LeBrun and co-authors said crazy ants may pose a greater threat to invertebrate and vertebrate species in woodlands than fire ants, which are scarce in such areas.
And because crazy ants reduce insect and spider populations, they’ll mean a reduction in food for wildlife that consume arthropods such as grasshoppers.
Researchers are searching for a biological agent to attack crazy ants.
Sustainable biological controls, such as a fungus, may be a cheaper, safer way to combat them than pesticides, LeBrun said. Another potential countermeasure is a tiny fly, which attacks crazy ants’ brains.
“I do think we can solve it,” LeBrun said. “The flies are doing great.”
John Austin covers the Texas Statehouse for CNHI’s newspapers and websites. Reach him at jaustin@cnhi.com<mailto:jaustin@cnhi.com>.