Aaron Johnson was worried when his two sons, ages 2 and 5, woke up complaining about painful bites that resulted in large welts on their legs.

At first he thought it was due to bedbugs in their Lanikai home, but a professional determined there were none.

Then he looked under the bed and saw tiny ants.

It turns out they were little fire ants, or Wasmannia auropunctata, an invasive species native to South America that can deliver painful stings.

They measure only about one-sixteenth of an inch long and are orange-red to light brown, according to the Oahu Invasive Species Committee, but are considered one of the world’s worst invasive species. They can infest homes and yards, cause blindness in pets, plus damage farm crops and forests.

And they are spreading rapidly on Oahu, where there are now more than 30 active sites of little fire ants across over 200 acres — from Kahuku down the entire Windward coastline to Hawaii Kai and Kahala.

There were four active sites of little fire ants detected at Lanikai homes in December, and they have also been reported along a beach access point and along foliage behind homes at the beach.

They have also been found recently in Kaneohe, Maunawili and Waiahole.

Those battling the infestations say the state needs to act quickly to stop the spread and prevent the establishment of more colonies on Oahu before it is too late.

The situation is at a tipping point, according to Christy Martin, who is with the University of Hawaii at Manoa’s Coordinating Group on Alien Pest Species. This is the worst she has ever seen it on Oahu.

“If we don’t do something now, what will happen is we will lose the opportunity to do something once it’s too widespread,” said Martin. “It will become impossible to get to points where we could declare eradication.”

This is what has happened on the east side of Hawaii island, she said, where residents have had to accept living with little fire ants instead of eradicating them. They now have to regularly treat their properties to protect their yards and homes to prevent re-invasions.

The state first detected little fire ants in 1999 at a nursery in Puna on Hawaii island, and they have since been found on Kauai, Oahu, Lanai and Maui.

And yet the entities working to stop the spread of the ants — including the Oahu Invasive Species Committee and the Hawaii Ant Lab — are underfunded, with inadequate staffing.

The Hawaii Ant Lab, a program of the University of Hawaii Pacific Cooperative Studies Unit, was granted $500,000 by the state Legislature to battle little fire ants statewide. There are only 2.5 staff members from the lab working to eradicate the ants on Oahu.

Martin said it is urgent that the state stop the spread of ants within the island of Oahu — and in particular, nurseries that continue selling plants with little fire ants.

Although the state Department of Agriculture should have the authority to prevent sales of plants infested with little fire ants, there are no administrative rules yet in place to do so. Additionally, there are no rules requiring the nursery to treat the plants or take steps to prevent further spread.

‘We know there are infected nurseries right now selling infected plants and materials,” she said.

The rules were drafted earlier this year, said Martin, but await a yet-to-be-scheduled public hearing.

Agricultural Department officials, in written response to Honolulu Star-Advertiser inquiries, said it will continue to inspect plant material for little fire ants and other invasive species from the Big Island to other islands.

Currently, interisland movement of infested plants is prohibited, but the department has had difficulty stopping the movement of such plants within an island.

Chair Sharon Hurd said the proposed rules are not ready for a public hearing because the department intends to revise two rule chapters with clearer language to prevent the movement of infested materials. Both of these rule chapters, she said, will be revised by July.

In the meantime, she said, the Hawaii Invasive Species Council, Hawaii Ant Lab and department will continue work to minimize populations and spread.

“HISC and HDOA will also be requesting additional funds specific to little fire ants control,” she said. “HDOA has and will continue to inspect plant material for little fire ants as well as other invasive species from the island of Hawaii to the other islands.”

Lanikai is ‘ground zero’

State Rep. Lisa Marten, meanwhile, has been walking door to door in Lanikai to let residents know there is a growing little fire ant infestation in the neighborhood.

Lanikai has become “ground zero” for the infestations, she said, which now includes the Mokumanu Beach Access, where little fire ants were confirmed by the Hawaii Ant Lab. The fire ants have also been found in foliage along eight spots behind homes.

“The beach access itself is crawling with them,” she said.

In a social media post, she warned people to be aware of the infested area, given that people are putting down their beach towels and toys in the area, and that pet dogs sniffing there could get stung.

“That’s a big concern,” said Marten, who authored the House bill appropriating funds for the Hawaii Ant Lab. “We have the ants and people are not paying attention.”

The Hawaii Ant Lab had earlier sent out a mailer seeking permission and contact information from residents to survey the area, and potentially start treatment, which is a yearlong process.

There have been ant infestations in Lanikai over the years. In May 2022 there were two listed by the Oahu Invasive Species Committee, followed by three more in August and then four more in December.

“If people would just know and respond, we could still possibly eradicate them,” said Marten.

Johnson said until his kids were bitten, he was not aware of the extent of little fire ant infestations in the area. He reached out to neighbors because he learned if they are at one property, they are likely at another.

Marten hopes the neighborhood can quickly get organized to eradicate them with a comprehensive treatment program.

Unifying the community

When Joseph Wat learned in early August there were little fire ants along Waihee Road near the Key Project’s community center in Kahaluu, he sprang into action.

Wat, who works for the nonprofit Key Project, went knocking on doors, galvanizing residents to test their backyards to find the “edges” of the infestation, and with everyone on board, the Hawaii Ant Lab initiated treatment Sept. 20.

As part of his job, he brings kids outdoors to connect with the aina, and little fire ants pose a threat. More funding and attention are needed he said, and everyone should be concerned.

“My ants are your ants and your ants are my ants,” he said. “If they are on the Windward side of Oahu right now, that does not mean they will not be in Waianae in 10 years.”

Community leaders also need to step up and coordinate action through testing, monitoring and mobilizing, he said.

“The only way we’re going to get these ants under control on Oahu is by an incredible community effort,” Wat said.

The Hawaii Ant Lab already has established treatment protocols, and eradication is possible if the ants are detected early enough, according to Martin of UH’s Coordinating Group on Alien Pest Species.

Eight treatments with ant bait every few weeks are needed with the goal of taking out the colony’s queen. The process takes at least a year, and monitoring continues for several more years.

“We know exactly what to do,” she said. “And we know that it works.”

The stoptheant.org website, which lists how active sites were recently detected, shows the extent to which little fire ants are affecting communities.

A Kaneohe resident in May sent in samples after his wife and baby were stung by ants in their backyard. The lab found an extensive population on both sides of a culvert there that extended downstream, and is still surveying the area.

In August a resident in the Kaelepulu, or Enchanted Lake, area of Kailua reported ants stinging him in his kitchen. The Hawaii Ant Lab confirmed they were little fire ants and found them on 13 properties covering about 3.3 acres.

A month later a local nursery in Waiahole reported suspected little fire ants, which were confirmed by the lab. The nursery voluntarily closed for treatment and is implementing best management practices.

As awareness about little fire ants and how to test for them grow, more sites are likely to be detected.

Concerned legislators, including state Rep. Scot Matayoshi, have been holding town hall meetings and education sessions on little fire ants on the Windward side.

“The Windward side is very impacted right now,” he said. “There are three infestations in Maunawili. … There are sites all over Kailua, Kaneohe, all the way up the coast. There’s one next to my house.”

A public hearing should be held as soon as possible, he said.

“It’s too late for the Big Island,” he said. “I don’t think it’s too late here. If we wait another year, it will be.”

REPORT INFESTATION

Little fire ants are an invasive, stinging ant. Their powerful stings can harm people and wildlife and lead to blindness in pets.

>> Survey your property using the chopsticks-and-peanut-butter test. Freeze the ants collected in a zip-top bag and mail in for verification. Free ant collection kits are available by request.

>> If you suspect little fire ants, report them to 643-PEST (7378).

>> Learn more at stoptheant.org.