Some good news in the battle against one of our more obnoxious invasive species.
Imported red fire ants have plagued farmers, ranchers and others for decades. Now the reviled pests are facing a bug of their own.
Researchers have pinpointed a naturally occurring virus that kills the ants, which arrived in the U.S. in the 1930s and now cause $6 billion in damage annually nationwide, including about $1.2 billion in Texas.
The virus caught the attention of U.S. Department of Agriculture researchers in Florida in 2002. The agency is now seeking commercial partners to develop the virus into a pesticide to control fire ants.
The virus was found in about 20 percent of fire ant fields, where it appears to cause the slow death of infected colonies.
"Certainly, we are excited about it," said Bob Vander Meer, the leader of the USDA research team in Gainesville, Fla. "I think the virus has great potential. No question about it."
In the laboratory, the virus, SINV-1, has proven to be self-sustaining and transmissible. Once introduced, it can eliminate a colony within three months.
That's why researchers believe the virus has potential as a viable biopesticide to control fire ants, known to scientists as Solenopsis invicta.
Although it occurs naturally in fire ants, the virus needs a stressor before it becomes deadly and begins replicating within a colony, Valles said.
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.