A Kaua’i nonprofit has built a community-driven map of coconut rhinoceros beetle infestations across the island, documenting feeding, breeding, and treatment sites as the invasive pest reaches Moloka’i for the first time and is rediscovered on Maui. The project, called Niu Ola Kauhale and led by E Ola Kākou Hawai’i, received a $25,000 county innovation grant and draws on a network of district leaders practicing traditional Hawaiian observation methods to gather data that state agencies lack the staffing to collect.
With Kaua’i’s state plant quarantine branch staffed by three people, project organizers and state officials say community-based mapping is the most practical near-term strategy for tracking the beetle’s range and buying time while scientists pursue landscape-scale biocontrol solutions.
Kaua’i farmer Fletcher Parker, one of the residents tracking the pest’s spread, described finding a dozen adult coconut rhinoceros beetles in a square foot of mulch within seconds. Over the following hours, he and roughly 10 others found hundreds of the beetles in a single mulch pile on the island’s South Shore. Coconut trees nearby showed V-shaped cuts — a sign of beetle feeding that Parker said is growing more common.
“People should be sounding the alarms,” Parker said.
Scale of infestation
Over two months of community workdays held in Wailua, Po’ipū, Līhu’e, and Anahola, E Ola Kākou Hawai’i volunteers collected 166 eggs, 2,539 larvae, 29 pupae, and 114 adult beetles. Between December and March, the project’s designated district leaders contributed over 700 data points to the map. About 70% of impacted trees showed low estimated damage levels, with only one to three fronds showing evidence of beetle feeding.
A single adult female CRB can lay up to 140 eggs in her lifetime. The insects spend most of their life cycle in decaying plant material, which makes detection difficult without deliberate survey work.
How the project works
The Niu Ola Kauhale project assigns a designated alaka’i, or leader, to each of Kaua’i’s four inhabited moku, or districts. Leaders engage in the traditional Hawaiian practice of kilo, or observation, surveying the number of trees affected, the severity of damage, and how long damage has been present.
Nākai’elua Villatora, the group’s po’o pani, or vice president, said the project is designed to mobilize the community to collect evidence and inform targeted mitigation in areas with high beetle activity.
“We all understand that it really does take all of us as a collective to combat such an invasive pest like CRB,” Villatora said.
E Ola Kākou Hawai’i has released a public-facing version of its map and now accepts community submissions, requiring photos with each entry so volunteers can verify findings before they are added. The nonprofit plans to update the map quarterly.
State resources fall short
CRB is considered widespread on both O’ahu and Kaua’i. The Hawai’i Department of Agriculture and Biosecurity’s plant quarantine branch on Kaua’i has three plant quarantine and pest control staffers.
Jonathan Ho, manager of HDAB’s plant quarantine branch, said the department cannot address the problem on all fronts simultaneously.
“It’s picking between bad or worse,” Ho said.
Ho said community efforts are helping the state gain time while officials weigh biocontrol options.
“We’re appreciative that the community is stepping up and biding time while the state is looking into biocontrol agents because that’s realistically the only landscape level solution for CRB,” Ho said. “We’re not going to spray our way out of this.”
Damage and spread
Chris Ka’iakapu, the district leader for Kaua’i’s Kona moku, which stretches from Kekaha to Po’ipū, estimated that 15% of trees in Hanapēpē have some CRB damage. He said E Ola Kākou Hawai’i’s map builds on a November field survey by a community group called Niu Now, whose co-founder examined 1,200 coconut trees between Kekaha and Hā’ena and documented heavy damage in Līhu’e-Wailua, Wailua Homesteads, and Kalāheo. That survey concluded that coordinated community efforts can slow or reverse the beetle’s spread.
Christine Chow, education and community coordinator for Nā Kahu o Hō’ai, a nonprofit that maintains Prince Kūhiō Park in Po’ipū, said limited state capacity shifts the responsibility to residents.
“With the state resources limited, you know, it always comes down to the community anyway,” Chow said.
A potential model for other islands
Arisa Barcinas, an outreach associate with CRB Response, a program managed through the University of Hawai’i, said the Niu Ola Kauhale map fills a gap no single agency has been able to address on its own.
“I think that’s what a lot of the community has been wanting but isn’t being mapped out too much by any one agency in covering all those things,” Barcinas said.
O’ahu nonprofit Aloha Organic maintains its own community map, but founder Daniel Anthony said he has not had the resources to expand it. Anthony said he plans to work with E Ola Kākou Hawai’i to share the Kaua’i model with other islands.
For areas where CRB has not yet established a significant presence, Barcinas said residents should report sightings to the appropriate agencies, including the state’s (808) 643-PEST hotline.
Originally reported by Noelle Fujii-Oride for Honolulu Civil Beat and distributed through a partnership with the Associated Press.