MANUKA, Hawai'i — The state's largest nature reserve will be closed for five days next month for a coqui frog eradication effort.

Manuka State Park and a portion of the Manuka Natural Area Reserve on the Big Island are to be off limits to the public March 6 to 10, the state Department of Land and Natural Resources said.

"We are taking these steps because we believe it is a priority to control coqui in a remote natural area where endangered species are threatened," agency Chairman Peter Young said.

Native to Puerto Rico, coqui frogs are noted for their loud shrieking. Populations of the 2-inch frog have become a big problem on the Big Island and Maui.

The two areas are being closed as a precaution while state crews spray citric acid, which kills the noisy frogs, Young said.

The areas were also treated in October and November, but another application had to be postponed because of consistent drought in December and January.

"This coming treatment will help to defend the area we have already covered, but there is a great deal of work yet to do," with another treatment later this year when more money will become available, Young said.

"If the entire area is treated, continuing monitoring and spot treating may successfully eradicate this isolated population," he said.

The Manuka Natural Area Reserve is the largest of 19 nature reserves on five islands, encompassing more than 109,000 acres of Hawai'i's most unique ecosystems.

The reserve extends from sea level to an elevation of 5,000 feet. It features sub-alpine shrub lands and forests, lowland wet and dry forests, wet mountain forests, lava marine pools and wet mountain kipuka forests, which are surrounded by lava flows.

"The Natural Area Reserves System is an irreplaceable legacy for the people of Hawai'i," Young said. "DLNR is committed to protect and manage these areas so that future generations can enjoy, study and experience the natural heritage which belongs only to our state."