UT scientists: Crazy ants may have finally met their match

University of Texas scientists have discovered a way to ward off crazy ants, an invasive species known to drive out native insects and small animals and even damage homes.

State of play: UT researchers found that a naturally occurring fungus can infect local populations of crazy ants without human intervention.

Why it matters: Tawny crazy ants, first discovered near Houston, have infested parts of the Gulf Coast region in recent years and are known to swarm breaker boxes, AC units, sewage pumps and other electronic devices.

• They're now found across the southeastern U.S. and nearly two dozen Texas counties, including Travis.
• Central Texas hasn't faced the same issues as parts of the Gulf Coast, but crazy ants have been spotted in Blanco and McKinney Falls state parks.

What they found: Edward LeBrun, a research scientist with the Texas Invasive Species Research Program at Brackenridge Field Laboratory, and his team observed populations of infected crazy ants.

• The team noticed that some crazy ants had abdomens swollen with fat. A closer look revealed spores from a microsporidian, a group of fungal pathogens.
• Microsporidian pathogens hijack insects' fat cells and turn them into spore factories.

The team also learned that every population that harbored the pathogen declined, with about 62% of those populations disappearing entirely.

• "You don't expect a pathogen to lead to the extinction of a population," LeBrun said. "An infected population normally goes through boom-and-bust cycles as the frequency of infection waxes and wanes."

What they did: The team brought already-infected crazy ants to nest boxes near crazy ant nesting sites in Weslaco's Estero Llano Grande State Park.

• The disease spread to the entire crazy ant population in Estero, and within two years, their numbers plunged.
• Now, they're nonexistent, and native species are returning to the area.

The good news: The pathogen leaves other native ants and insects unharmed.

What's next: UT researchers plan to test the new approach this spring in other Texas habitats infested with crazy ants.