first_imgRed imported fire ants aren’t the only fire ants causing havocacross Georgia. Now they’ve got company.A new hybrid fire ant, a cross between the red and the blackimported fire ant, can now be found across northern Georgia.Georgia’s northern counties were free of fire ants until 1985when the county Extension agent in Rome, Ga. reported findingfire ants in his county. Researchers first thought these wereblack imported fire ants that had traveled from northern Mississippiwhere they thrive.”We collected a sample of those ants and took them tothe (U.S. Department of Agriculture) laboratory in Gainesville,Fla., to be identified,” said Wayne Gardner, an entomologistwith the University of Georgia College of Agricultural and EnvironmentalSciences.They Look Alike”At first they thought the ants were red imported fireants,” Gardner said. “But after a chemical analysis,they discovered they were actually this new hybrid.”To the untrained eye, the ants look very much alike.They’re so similar, in fact, that scientists haveto use laboratory techniques to tell them apart.”The hybrids are almost totally black, so they look morelike the black imported fire ants,” Gardner said. “Butthe soil in the area actually dictates the color of the ants.In sandy soils they look lighter, and in clay soils they lookdarker.”UGA entomologists have compared the hybrid and the red importedfire ant and found they’re tolerant to the same temperatures.”They both survive the same length of time in cold temperatures,and they can both be controlled by the same pesticides,”Gardner said.So why do the black ants seem to survive in the colder areasof the state?How Are They Different?”Sharp changes in temperature really tell a tale on fireants,” said Gardner. “The hybrid forms may have adaptedsome sort of behavior that allows them to survive when the temperaturedrops. Or they may travel further underground than the red ants.We just don’t know yet.”UGA entomologists are continuing to study the ants’ differencesand similarities. This summer they plan to study the effectivenessof biological control methods on the hybrid fire ant.”We have released a parasite in south Georgia to fightthe red imported fire ants, and we know it works,” Gardnersaid. “Now we plan to release a new parasite against thehybrid and see how effective it is.”Gardner’s research coordinator, Stan Diffie, has collectedfire ants across the state and had them analyzed.”Prior to 1980, Interstate 20 was thought to be the northernmostboundary for fire ants in Georgia,” Gardner said. “Thenfire ants began to appear in areas north of I-20.”All Georgia Counties InfestedUGA entomologists’ surveys show that the hybrid fire ant reallyinvaded the state from Alabama. They moved into the northwesternpart of Georgia. Now all 159 Georgia counties report fire antinfestations.”Their invasion certainly helped the fire ant to coverour entire state very rapidly,” Gardner said. “We havefound that Interstate 85 serves as a kind of imaginary boundarybetween the hybrid and the red imported fire ant. South of I-85,all the ants are red, and north and west of I-85, all the antsare hybrid ants.”So which one’s worse, the hybrids or the reds?”Both forms are bothersome, but, so far, the black isrestricted in its range, and the red is far more aggressive,”Gardner said. “But to homeowners, it really doesn’t matter.They just want them all dead.”last_img read more