OVERTON Zombie fire ants may not sound like a cool thing, but wait a minute, said a Texas AgriLife Extension Service expert.
On April 29, on the grounds of the Texas AgriLife Research and Extension Center at Overton in East Texas, Dr. Scott Ludwig released fire ants infected with a new type of phorid fly, a minuscule parasite that only preys on red imported fire ants.
The infected ants will soon exhibit some very bizarre behavior, he said.
"First they become zombies, their movements under the control of the parasite. Then their heads fall off and the parasite emerges," said Ludwig, , AgriLife Extension integrated pest management specialist.
Previously released phorid flies only preyed on ants in disturbed mounds. In contrast, the species, Pseudacteon obtusus, that Ludwig released in April is attracted to foraging red imported fire ants and not disturbed mounts. Which is even better, he said, as attacks of ants are not dependent upon the mounds being disturbed.
The "zombified," fire ant is made to wander about 55 yards away from the mound to die.
"The parasite does this so it can complete development without being detected and attacked by the fire ant colony," Ludwig said. "By making their hosts wander away, the parasite is insuring its survival."
As with the new species, the previously released phorid fly species in Texas only attacks red imported fire ants. They inject their eggs into their bodies. In response, fire ants withdraw to their underground nests and reduce their foraging range, he said.
Once established, it was hoped that earlier releases of phorid flies would spread beyond the original release sites, and there has been evidence that they have, Ludwig said.
"Pseudacteon tricuspis was first released near Austin in 1995. From 2003 to 2006, it spread over 10,000 square miles," Ludwig said. "The second species, P. curvatis, was established 2004 and is beginning its spr
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Texas A&M AgriLife Communications