Red Fire Ants Facing Killer Virus

In this undated photo released by Texas A&M University, shown is an fire ant mound. Researchers have pinpointed a naturally occurring virus that kills fire ants, which arrived in the U.S. in the 1930s. The U.S. Department of Agriculture is now seeking commercial partners to develop the virus into a pesticide to control the critters. (AP Photo/Texas A&M\Bart Dress) (Bart Drees - AP)

Integrating the virus into ant baits could offer a tool to the pest-control industry, agricultural producers and harvesters, consumers and others for whom fire ants are a persistent problem.

The virus isn't alone in the fight against the fire ant. In South America, they have dozens of natural enemies. But researchers don't know whether those predators could be introduced here.

Among them is the small phorid fly, which seeks out fire ants and lays its eggs on them. The eggs hatch into tiny maggots that bore into the heads of their host and feed on its brains.

"The problem is we really don't know how effective these phorid flies are going to be in North America," Merchant said.

Some Texans may have thought the fire ant problem was improving. Drought conditions across much of the state in recent years have only driven them deeper under ground.

"One thing you can thank the dry weather for is it keeps the fire ants down," said Mike Merchant, an extension entomologist in the cooperative's Dallas office.

This year, wet conditions have returned and that will increase pests' visibility.

"I think those fire ants are waking up," said Bart Drees, an entomologist with the Texas Cooperative Extension in College Station.

The fire ant isn't all bad. As omnivores, they eat just about anything and can reduce tick populations in pastures and yards. Also, cotton and sugarcane growers see them as helpful. The ants munch on boll weevils, caterpillars and sugarcane borers.

"But on balance they're an ecological disaster," Merchant said. "The good that they do is far outweighed by the negative."

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On the Net:

Extension: http://www.extension.org/fire+ants

Texas A&M University's Imported Fire Ant Research and Management Project: http://fireant.tamu.edu/