The number of palm-damaging coconut rhinoceros beetles discovered on Oahu continues to rise, with the count close to 2,000 for adults and immature stages uncovered along the isle’s south coast, a state official said Wednesday.

“That number increased significantly on us last week” when about 500 larvae were found at the Marine Corps’ Puuloa Range Training Facility in Ewa Beach, said Rob Curtiss with the Hawaii Department of Agriculture, who’s leading the beetle eradication effort.

As of July, 540 adult beetles, 600 larvae and 16 pupae had been detected on Oahu, the state said.

Curtiss said the beetles’ known range is from Sand Island to Campbell Industrial Park. From Sand Island to around Fort Shafter and to the west “is roughly where we would say that they are,” he said.

The coconut rhinoceros beetle, a serious invasive pest, was detected on Dec. 23, 2013, on Joint Base Pearl Harbor-Hickam, according to the state.

About 120 palms with beetle damage were cut down on Hickam, with most of those on Mamala Bay Golf Course, which is close to Honolulu International Airport, the Navy said.

Officials say they don’t know how the pests arrived, but flights from elsewhere in Asia and the Pacific are seen as a possibility.

On Wednesday, state officials and the Navy demonstrated the operation of an “air curtain burner” near the golf course to incinerate beetle-damaged palm tress.

The burner, a large metal box over which is blown a curtain of air, keeps down emissions and accelerates burning, officials said. The device can burn three to five tons per hour, the Navy said.

Four more air curtain burners are being brought in by the Navy, more manpower is being devoted to the beetle eradication effort, and millions in funding will be needed for years to come to control the pest, officials said.

The U.S. Department of Agriculture has allocated $2.8 million this calendar year to the effort, the state between $1.1 million and $1.2 million, and the military over $2 million, Curtiss said.

About 2,200 black hanging “panel traps” have been put up around Oahu to trap flying beetles, and that number is expected to increase to 3,000, Curtiss said.