April 8, 2013 9:20:01 AM
BATON ROUGE -- April is the time for neighborhoods to get together to fight fire ants and for farmers to attack the critters in pastures and hay fields, experts say.
Experts say the most effective treatment is baits designed for fire ants. They don't hurt helpful insects because the ants forage for food, pick up bait and bring it to the nest to feed other ants. Eventually, the chemical finds its way to the queen.
"Once they get the bait into the colony, it works its way into the system," said Linda Hooper-Buí, an entomologist at the LSU AgCenter. "Then the colony dwindles and dies."
She said that if you only treat your own yard, fire ants can return from nearby yards -- but treating large areas can help eliminate colonies.
"It doesn't matter if everyone uses the same product or not," she said. "But it's important that all residents treat their yards. Get the people on your block together, purchase fresh bait -- fresh baits are most attractive to ants -- and attack the problem together."
Experts at the Mississippi State University Agricultural Extension Service say it doesn't make sense to buy more bait than you can use in one season. The poison or growth regulator is made attractive to ants by mixing it into grits coated with oil. If it's kept too long the oil will go rancid, making the bait unattractive.
Nor does it make sense to use more than the label recommends. "Don't be tempted to apply excessive rates in order to 'really get 'em,'" the MSU fact sheet states. "If you are willing to spend more money for improved control, it's much better to spend it on a second application later in the season!"
Most granular baits need only a pound or two per acre, the extension service said.
"This is not very much bait, and it is easy to over-apply and waste a lot of money if you don't have a proper applicator," its fact sheet notes. "A typical fertilizer spreader will put out far too much bait. And it is not a good idea to mix the bait with fertilizer because the fertilizer will absorb some of the oil from the bait granules, making them less attractive to the ants."
Most baits can be used in residential, recreational and landscaped areas but only a few should be used in cropland, pastures, hay meadows, orchards or vegetable gardens.
Treating the area in April gets the bait to the ants before they begin multiplying during the warm summer, she said. A second treatment later in the season will help control any colonies that escape the first bait application.
Baits generally take a period of time to eliminate a colony -- anywhere from a week to a month, depending on the chemical used.
"Bait products don't protect against reinvasion by ant colonies from surrounding land or by newly mated queens," Hooper-Buí said. "And populations can fully recover within 12 to 18 months of the last bait treatment."
Baits should be applied when grass is dry, rain isn't expected for another day or two and fire ants are actively foraging. To check on that, scatter a few greasy potato chips near a mound and return in 20 to 30 minutes. If ants are on the chips, they'll find the bait.
■ Neighborhood treatment: bit.ly/11x4FdU
■ Pasture treatment: msucares.com/pubs/publications/p2493.pdf
■ Fruit & vegetable land treatment: msucares.com/pubs/publications/p2494.pdf
■ General info: uaex.edu/other_areas/publications/pdf/fsa-7036.pdf