Aloha, Neighbors.

I’m Ruby, an artist made and raised on Kauai. For immediacy, I’m hosting this page on my site while a fully interactive website dedicated to CRB is being fleshed out. This preliminary information below was compiled by Auntie Merlyn Ruddell as a result of a North Shore community meeting where experts and neighbors communed to share research and experience preventing and treating the destruction caused by the Coconut Rhinocerous Beetle, with toxic pesticides as a last resort.

To be added to a mailing list for news and updates, send your contact info to PeacefulKauai@gmail.com or text Merlyn at 808-828-9891. Soon, she will be providing a more detailed report, prepared by E Ola Kākou Hawaiʻi.

In solidarity!
Ruby

What is a Coconut Rhinoceros Beetle (“CRB”)?

  • Lethal to coconut palms

  • Adult CRBs up to 2 or 3” long 

  • Adult CRBs bore into the crowns of palms

  • Feed on the developing leaves and sap

  • Lay eggs in decaying organic matter such as rotting coconut logs, mulch, compost piles 

  • Adult beetles are nocturnal and can fly several miles in search of food or breeding sites

  • Adult females lay between 50 to 140 eggs during their lifetime

What do Larvae look like and how do they multiply? 

  • Larvae: The eggs hatch into C-shaped larvae that can grow to be up to four inches long.

  • Larvae live in mulch piles, fallen coconut logs, green waste. 

  • Spread through transport of infested green waste, mulch, soil, and compost.

What is the danger of CRBs?

  • Damage and destroy coconut palms widely and thoroughly

  • Secondary targets include palms, taro, hala, pineapple, papaya, banana, and sugar cane

  • Spread rapidly

  • Guam - First detected in in September 2007  

    • Then spread became entrenched, despite control measures like pheromone traps, sanitation, and biological controls

    • Guam Department of Agriculture estimates that at least 25% of coconut trees have sustained damage from CRB  

  • Established on Oʻahu since its initial detection in December 2013

    • Spread island-wide

    • CRB now considered present throughout Oʻahu

    • Localized hotspots, such as parts of the North Shore and Pearl City, have reported up to 50% mortality in coconut palms

Is there a cure for CRB infestation or an effective statewide effort to eradicate CRB?

  • Not as yet

When was the first CR Beetle found on Kauai?

  • The first CRB was found at the Lihue transfer station in 2023

  • Kauai was the first neighbor island to report a detection

  • Breeding sites were soon found in Puhi, Wailua and Kīlauea

Two years later, where are CRB damaged and dying coconut palms and/or breeding sites on Kauai’s North Shore?

  • Anahola

  • Aliomanu

  • Moloa’a

  • Kilauea

  • Princeville

  • Hanalei

“Kaua‘i’s landscape is essentially a perfect breeding ground for CRB,” wrote Keanini and Chock. “We have a lot less urbanized areas as compared to O‘ahu and many large green spaces with decaying matter that can serve as potential breeding sites as long as feeding material is available nearby.”

How do I know if I have CRB or CRB larvae?

  • Pheromone Traps (pheromone traps are for initial detection only, as they attract CRBs to the area - for a deterrent, use non-pheromone traps only - such as UV traps)  

  • Go through all green waste on your property with scent dogs and experienced handlers

  • Comb through all decomposing material on your property, and look for larvae

Visual inspection of Coconut Palms: 

  • Center shoot of coconut palm leans over

  • Palm fronds have distinct V-shaped cuts

  • Holes along the center of the frond's midrib

  • Tips of fronds are stunted/cut

  • Edges of fronds are eaten

  • 2-inch boreholes in the palm's crown where the beetle initially feed

NOTE: CRB LOOKALIKES!

It is important to note that some other beetle larvae look like CRBs but are NOT, and are NOT harmful, like the Oriental Flower Beetle (OFB). OFBs move like an inchworm, while CRBs move on their sides, always trying to curl and burrow. Here is Lance Thomas, mentioned below with Conservation Dogs, explaining the visual difference. On the LEFT side of the screen is a CRB, on the RIGHT is an OFB .

 What to do if I find CRB larvae?

    • Comb through every bit of the pile and drown them

    • Heat the pile to 135 degrees

    • Report it to 808-643-PEST or https://www.643pest.org/

    • Submerge larvae in water

    • Cover mulch/green waste pile thoroughly and expose to sunlight to heat pile interior to over 135 degrees Fahrenheit
        

What do I do if I find Coconut Rhinoceros Beetles or Beetle-Damage in my Trees? 

How do I prevent CRB?

  • CRB flourish in compost and green waste piles 

  • Remove standing dead coconut palms, coconut stumps & logs

  • Inspect commercial potting soil, fertilizer etc for CRB/larvae/eggs

  

 Prevent/Protect through Green Waste management:

  • First choice: Remove green waste and compost piles

    • Take green waste to the Transfer Stations or Heart and Soul Organics in Moloa’a

  • Second choice: Manage green waste onsite

    • Solarize - wrap in plastic and heat - 135 degrees kills larvae

    • Chip green waste, etc, as long as no larvae are present. & spread the chips like confetti, not chip piles 

    • Add chicken fertilizer; nitrogen & calcium deter larvae

    • Spread mulch under trees no higher than 10”

        • Keep material dry and well-aerated

        • Avoid letting green waste accumulate in shaded or moist areas.

        • Regularly turn compost piles to expose larvae and interrupt their life cycle.

 

Prevent/Protect through Coconut Palm ongoing management:

  • Trim coconut palms - Prune, remove brown fronds & dirt clumps

  • Build the health of coconut palms & boost immunity

  • Fertilize, foliar spray, (see list below) and seawater

  • Regular Application of non-toxic deterrents in crown

    • Treat coconut crowns to repel beetles with a mixture of some or all of the following:  Basil oil.  Dr. Bronner’s Peppermint Soap, Sand and Sea Salt, Neem “cakes”

    • Stuff into crooks of coconut leaves. get as high up in canopy as possible where CRB prefers to feed

    • Tuck moth balls in soda cans into crowns - place two moth balls in dry cans & fold over to keep mothballs dry

    • Diatomaceous earth (use with caution)

    • Netting (special netting with small holes) has to be adjusted for each new frond, labor intensive

Soda can, rinsed and dried, with 2 mothballs pushed inside; BEND IN HALF, HOLE DOWN to avoid RAIN. Tuck into nooks near COCO PALM crown (CREDIT: MAKANA MARTIN)

What are some natural predators for CRB?

  • These predators are a valuable part of the management strategy

  • Pigs, Chickens, Rats, Centipedes

  • Their overall impact on the CRB population is limited:

  • Known to consume CRB larvae, especially those found on the surface of breeding sites

  • Will eat beetles and eggs on infested compost if it’s spread

What about using commercial pesticides?

  • Take several months to be effective

  • Must remove fruit and flowers

  • Cannot use fruit or water for years in the future

  • Toxic to humans and animals

  • Leave residue in soil and water 

  • Must be reapplied to remain effective

What can I do about CRB in my neighborhood?

  • Individuals and groups on Kauai working together can protect and preserve coconut palms and other precious crops in their neighborhoods 

  • Spread the word to friends and neighbors

  • Tell your neighbors of any larvae, beetles or tree damage in the area

  • Forward this report 

  • Gather and coordinate efforts

  • Find out if there are infestations in your vicinity and eliminate them

  • Advocate for eliminating breeding sites, like compost piles

What can I do about CRB on Kauai and in the State of Hawaii?

  • Apply political pressure to fund CRB research

  • Write letters to decision makers (form and email addresses will be sent out to the mailing list shortly)

  • Demand necessary funding and action at the County and State level 

Whom can I contact for help?

St. George!  

The icon of St. George the Victorious is a symbol of courage, faith and the victory of light over darkness. Saint George is revered as a defender of faith, warriors, farmers and all those who need help. His image inspires us to fight against difficulties and evil.