PUPUKEA (KHON2) — Many North Shore residents are starting to see a change in the landscape with palm trees being infested by the Coconut Rhinoceros Beetle.
From Mokuleia to Laniakea, to Pupukea, and from Ke Iki to Sunset Beach, if you look up you’ll see palms with only a few fronds, some with none, and some looking sick or oddly shaped.
“I just kind of noticed how a lot of the palms on the North Shore were getting infected by CRB,” said North Shore resident Brent White, who also owns Lush Palm Landscapes. “And it just started working its way down the mountain from Mililani, and I started saying to myself ‘I don’t think anybody’s out here is saying anything about it on the North Shore, and people were kind of unaware, and especially with the landscaping business, they were asking me ‘Are my palms, okay?”
He started educating people on what they could do right away to help prevent the beetle from spreading in the area and even started his own Instagram page to help get the message out on @Oahucocorb.
“Mitigate mulch piles and compost from your yard,” White said. “The biggest thing I’ve seen is grubs (which are the larvae and are sluggish, white, ‘C’-shaped that can grow 2.4 to 4 inches or more) in composting material, wood chip piles, and in green waste on people’s properties.”
He said he can find up to 50 grubs in some of the mulch piles. Experts say female CRB can lay up to 100 eggs in their lifetime.
“What’s happening is the beetles are flying around in the local area and they’re finding these piles and they’re inundating them and they’re laying eggs,” White explained. “And then you’re creating more of a beetle population and then it gets harder to stop the beetle because there’s more CRB flying around and attacking the palms.”
He said he and others are working on natural solutions to protect the trees. Experts with UH Manoa said anyone using natural solutions should be mindful that the rain can wash any treatment away and has to be reapplied often.
Experts said it’s not too late to call someone to look and treat your tree, even if it’s already showing signs of being infested, the earlier the better.
“When you have very few fronds on the tree I think you need to make a decision to call someone and you need professional help to see if it’s savable or not,” Christy Martin, Program Manager for the coordinating group on alien pest species at UH Manoa said. “In some cases, they have enough energy left if you do insecticide treatment maybe you can rescue the tree but sometimes they won’t be.”
She said dead palms need to be professionally removed and quarantined.
“If it’s a dead tree, we’ve seen it before, it becomes a beetle condo hotel for breeding, and it needs to come down,” she said.
She added the beetles not only will breed inside of the dead tree, but it can become a safety hazard too as the beetles absorb all the moisture, which can lead to the tree falling down. The area below a dead tree is also a breeding ground for beetles which is why they need to be professionally removed and quarantined ahead of removal.
“It’s hard to imagine Hawaii without coconut palms, or any palms, it’s hard to imagine Hawaii without hala, we have to do a better job.”
Christy Martin, UH Manoa Alien Pest Species program manager
Martin said the beetles are active at night and go after the sap at the heart of the palm.
“They are feeding on the sap of palms, it can be coco palms, date palms which there are a lot of on the North Shore or fishtail palms,” she said.
KHON2 took a video of palms outside Ehukai Beach Park in September 2023, and then again this past week. Eight months later, you can see how much damage the beetle has done.
“When you see trees with damaged fronds, it takes months for it to get there,” Martin explained. “So you’re seeing pretty advanced infestation on the North Shore.”
The CRB map shows heavy infestation in Pearl City, the leeward coast, central Oahu and now North Shore, but little activity on the windward side. Martin said it’s only a matter of time until it reaches there.
“I think what we’re seeing on Oahu is the spread is still around where it was originally detected around Joint Base Pearl Harbor, and that spread towards the Ewa side where there are a lot of coconut trees, and then up to the middle of the island,” she explained.
“I’m not ready to give up quite yet, we do have to work harder to protect the trees we have left,” she added.
This year, the legislature passed a bill investing roughly $20 million to staff and fund programs targeting invasive species, which is pending the governor’s signature.
She said they don’t have enough tools in the toolbox to test different treatments to find the end-all solution, but hopes the Dept. of Agriculture can get the money and find out what to do.
In the meantime, Martin said wrapping fishing nets around the crown can help protect shorter palm trees, and it’s not too late to call a company to look at your tree for treatment.
Also, be aware of any soil you buy from the store. If you have the time, quarantine the soil outside before laying it out. Also, while you’re at the store, look to see if there are any holes in the bag. If there are any larger than your thumb, it could be an adult beetle made its way out of the bag.
Martin also said CRB are targeting kalo, hala, and banana too.
“It’s so hard, the response to it has been slow,” she said. “We’ve been dealing with this since we learned about it in 2013, and great job containing it for so long but it’s at the point now where we have to change it up, and we need more tools.”
Neighbor islands should call 808-643-PEST if they see any unusual signs in trees to help prevent the spread right before it’s too late.