HILO — As it dismantles the last vestiges of its coqui-control program, Hawaii County plans to sell off the equipment some community groups say is essential to their voluntary eradication efforts.

The move comes just as scientists say the county's coqui population is maturing into much larger frogs. Where once they were described as the size of quarters, a coqui was recently reported the size of a tennis ball, said Mark Munekata of the Hawaii Island Economic Development Board.

"The coquis don't have any budget cuts," Munekata said, adding that the frogs seem to rapidly adapt to Hawaii conditions. "Once you think you understand them, they do something else and throw you for a loop."

Munekata, and scientists from the University of Hawaii at Hilo and the state and federal departments of agriculture, appeared Tuesday before the Hawaii County Environmental Management Committee.

County and state governments once poured millions into eradication efforts. But the economic downturn has forced governments to prioritize their spending, and the uphill fight against the coqui was among the first to go.

Coquis are considered a threat to native wildlife because of their huge appetite for bugs. People also complain about their shrill chirp, which reaches 80-90 decibels, comparable to the loudness of a lawnmower.

Dave Douglas, a member of Hamakua Individuals Joining Against Coquis, or HIJAC, said his community group of about 25 people chips in for pesticides used in the sprayer that's on loan from the county.

He said the county wants them all back and plans to put them up for auction as surplus next month. He said the 200 gallon sprayers are valued at $3,500, and the 400-gallon ones go for $6,500, and HIJAC doesn't have that kind of money.

That bothered South Kona Councilwoman Brenda Ford, who asked why the administration is taking them away when the community is doing the labor and providing the chemicals for localized control efforts.

"It seems kind of unfair that the county would consider selling off the sprayers," Ford said.

Contacted after the meeting, Finance Director Nancy Crawford said she thinks some of the sprayers belong to the USDA and must be returned. She said since the county is no longer involved in coqui control, it makes more sense to sell the equipment "and put it in the hands of people that can use them."

Scientists discussed a range of ways to curb coquis. Chickens can clear areas of coquis and produce eggs at the same time.

"I get eggs, I get fertilizer and I get no coquis," Mountain View resident Janice Parker said.

Munekata prefers baking soda over the two current legal eradication chemicals — hydrated lime and citric acid.

But Lyle Wong, head of the Plant Industry Division for the state Department of Agriculture, said he'd be obligated to "take action to prevent further use" of unapproved materials such as baking soda and another chemical under consideration, acidic calcium sulfate, marketed as Agent Green.

In other business, the council's Committee on Public Works and Intergovernmental Relations voted 4-2, with three members absent, to send a negative recommendation on a resolution setting a voluntary $2,500-per-day fee for private aircraft using the Kona or Hilo airports.

The resolution, sponsored by North Kona Councilman Kelly Greenwell, needed five votes to get a positive recommendation.

"We might be missing the boat here," said Ka'u Councilman Guy Enriques, who along with Hilo Councilman Donald Ikeda voted no. "But I totally get what you're driving at."