Texas A&M turns up the heat on fire ants

College Station, Texas

-- Researchers are experimenting with a tiny fly to take the sting out of the power of fire ants, which can threaten young calves.

Researchers at the University of Texas at Austin and Texas A&M's AgriLife Extension Service say a tiny phorid fly -- imported from its native South America -- has pathogens that attack fire ants to help keep their population and movements under control.

The flies work by attacking fire ant colonies and laying eggs. The eggs hatch inside the ants, then eat away at their brain, causing the ants to exhibit what the researchers have dubbed "zombie-like" behaviors. The maggots eventually travel to the ant's head, and the ant starts to wander aimlessly away from the colony. About a month after the egg is laid, the ant's head falls off and the fly emerges, ready to attack another colony.

"The parasite does this so it can complete development without being detected and attacked by the fire ant colony," says Dr. Scott Ludwig of the AgriLife program. "By making their hosts wander away, the parasite is insuring its survival."

The flies therefore help to reduce the foraging area of fire ants, who after an attack will withdraw to their underground nests, Ludwig says. The phorid fly does not attack any native species, he adds, only red imported fire ants.

The flies are approved by the U.S. Department of Agriculture and only have been introduced in Gulf Coast states. Farmers and ranchers have cooperated with the study by allowing researchers to establish colonies on their property. Their effectiveness in the fight against fire ants in Texas will be slow and could take as long as a decade, though, adds Ludwig.