State agricultural officials Friday released the details of a plan designed to rid Oahu of the little fire ant, a tiny pest described as one of the world’s worst invasive species.

Starting in a few weeks, Hilo’s Hawaii Ant Lab will direct state crews in the treatment of a 3.5-acre area of Wai­ma­nalo — plus a 2.5-acre buffer zone — using a combination of pesticide baits. The treatment will be repeated at least eight times over a 12-month period, said Robert Curtiss, acting manager of the state Department of Agriculture Plant Pest Control Branch.

If the area is clear of the ants at the end of the 12 months, the treatment will end, and monitoring will continue for three years, he said.

"We’re certain we can eradicate it," Curtiss said at a Hono­lulu news conference. "It will take the one year plus three years of monitoring before we know for sure."

Officials are hoping to avoid the fate of Hawaii island, where the little fire ant was discovered in 1999. The ant is now found all over the island, causing an estimated $130 million a year in economic damage ranging from the loss of farm productivity to the cost of controlling the ants in public areas, officials said.

A University of Hawaii study estimated that Oahu could face $170 million a year in losses if the pest is allowed to spread unimpeded.

Curtiss said the repercussions of doing nothing are too great.

"It will affect all aspects of life here in Hawaii. It will affect tourism. It will affect farming. It will affect our economy. It will affect even just staying at home. On the Big Island, people are reporting the ants coming into their homes and stinging them in the night. So if we did nothing here and let it get out of hand, it would be a situation we couldn’t live with," he said.

The Waimanalo infestation was discovered March 27 in routine Department of Agriculture surveys outside some nurseries in Wai­ma­­nalo.

In the following weeks, officials conducted a survey covering more than 50 acres, from Kumu­hau Street to Mahai­lua Street, and collected 1,500 samples, of which 60 were positive for little fire ants.

From the size of the infestation, it appears the ants have lived in the area undetected for a couple of years, Curtiss said.

Officials have already started to cut roads and trails into the area’s dense jungle in preparation for the eradication effort, which will see crews applying a combination of general-use pesticide baits, including Tango (S-methoprene in gel bait matrix), Probait (hydramethylnon) and Siesta (metaflumizone).

The price tag of the eradication effort has not been determined, Curtiss said, but it is expected to cost no less than "tens of thousands of dollars" by the time it’s over.

Originally from South America, the little fire ant’s painful sting can produce large red welts and can cause blindness in pets. They are only one-sixteenth of an inch long, but they can build up enormous colonies on the ground, in trees and other vegetation and in buildings and homes, and completely overrun a property.

"Some people say, ‘It’s just an ant. We’ve got ants.’ No, this one is different. It needs to be treated differently," said Neil Rei­mer, acting administrator of the department’s Plant Industry Division.

Officials urged homeowners to help the state survey their yards by placing a chopstick smeared with peanut butter outdoors for about one hour and then putting the stick in a sealable plastic bag. Freeze the sample for at least 24 hours and then send it to the department. Instructions are at hdoa. hawaii.gov/pi/files/2014/01/Survey-LFA-public-2014-01-29.pdf.

Suspected invasive species should be reported to the state’s toll-free pest hotline at 643-PEST.

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