State, county collaborate efforts to combat coconut rhinoceros beetle in Kona

The fight against an invasive scourge that could decimate the Big Island’s palm trees — and other important plants — wages on, with efforts focusing in West Hawai‘i since the scarab was first detected on the island nearly 2 years ago.

Hawai‘i Department of Agriculture and Hawai‘i County Public Works have collaborated since January to combat the coconut rhinoceros beetle by treating palm trees in the Kona airport area after its was first detected in the Kona area.

State and county crews completed the latest round of treatments on palm trees last week at Ellison Onizuka Kona International Airport in continuing efforts to protect the island from becoming infested by the invasive scarab.

They then moved on to treat palms in the nearby Natural Energy Laboratory of Hawai‘i area.

“The staff of the Department of Agriculture remains dedicated to stopping the further spread of the coconut rhinoceros beetle, with emphasis in areas that are not known to be infested,” said Hawai‘i Board of Agriculture Chairwoman Sharon Hurd in the department announcing the agencies’ continuing fight. “We truly appreciate the concern and assistance of [Hawai‘i County] Mayor Kimo Alameda and the county’s Public Works crew in providing the resources to prevent [coconut rhinoceros beetle] from taking hold on Hawai‘i Island.”

Hurd added that the state Agriculture Department also appreciates all the various other agencies and organizations that work tirelessly in the fight against invasive species.

State Plant Pest Control personnel in September 2024 found a single coconut rhinoceros beetle in a trap during routine monitoring in Waikōloa — the first time the invasive pest was detected on the Big Island since October 2023, when a Waikōloa resident found six grubs in a decaying palm tree stump.

Increased surveillance continued around the island, even more intensely on the Kona side.

Alameda and Hawai‘i County offered their resources and assistance to the state Agriculture Department in January, including the use of the county’s 75-foot boom truck, to treat crowns of palm trees.

The team treated a total of 38 trees Jan. 14 in the Waikōloa area via crown treatments and 24 were treated via an injection system, which provides systemic protection against coconut rhinoceros beetles.

Department of Agriculture Pesticides Branch was also at the site to assist.

So far, there have been no further detections of the invasive beetle in Waikōloa.

Big Island Invasive Species Committee reported March 3 that one adult coconut rhinoceros beetle was found in a trap along the boundary of the Ellison Onizuka Kona International Airport.

A day later, two more adult beetles were found in traps at the nearby Natural Energy Laboratory of Hawai‘i.

State and county crews along with airport staff targeted treatments at the airport during a period of 3 days in March following the discovery of the beetles.

With the county providing the use of two boom trucks, crews were able to treat 128 trees on the airport grounds and injected 12 more trees that were inaccessible to the boom trucks.

So far, there have been no further detections of coconut rhinoceros beetle at the airport.

Crews on April 7-8 began work at Natural Energy Laboratory of Hawai‘i, treating 58 trees via crown treatments, with about 14 trees treated via injections because of their close proximity to water.

All treated palms were tagged and surrounded with yellow tape. Coconuts from treated trees should not be consumed.

Surveillance for coconut rhinoceros beetles continues around Hawai‘i Island by Hawai‘i Department of Agriculture, Big Island Invasive Species Committee, University of Hawai‘i, Hawai‘i County and Hawai‘i Department of Health Vector Control Branch.

Alameda emphasized the importance of the state and county working collaboratively to protect the island from the invasive species.

“The introduction of the coconut rhinoceros beetle is a major concern, and we are committed to doing everything we can — alongside [Hawai‘i Department of Agriculture] and our other partners — to stop its spread,” he said.

Residents on all islands are asked to be vigilant when purchasing mulch, compost and soil products, and to inspect bags for evidence of entry holes. The beetle breeds in decomposing plant and animal waste.

An adult beetle is about 2 inches long, all black and has a single horn on its head.

Residents can visit the CRB Response website to learn more about how to detect the signs of coconut rhinoceros beetle damage and how to identify the beetle’s life stages.

Reports of possible infestation can be made to the state’s toll-free Pest Hotline at 808-643-PEST (7378).

Questions about pesticide use for palm tree treatment can be addressed to the state Agriculture Department Pesticides Branch at 808-973-9402.