image from Hawaii Invasive Species Council website

(BIVN) – A new rule will restrict the movement of palm plants and organic material in Hawaiʻi, as the island state tries to stop the spread of the invasive coconut rhinoceros beetle, or CRB.

The Hawai‘i Department of Agriculture on Friday established a new interim rule prohibiting certain plant materials from CRB-infested areas from entering non-infested areas in the state.

The Advisory Committee on Plants and Animals recommended approval of the interim rule. It restricts the movement (from infested areas to non-infested areas) of:

• palm plants
• decomposing plant material, such as compost, wood or tree chips
• mulch
• potting soil
• other landscaping products that may harbor CRB
• palm plants higher than four feet in height, which will enable closer inspection of palm crowns where CRB are most likely to bore into a tree

The entire island of Oʻahu has been designated as a CRB-infested area.

On Hawai‘i Island, “CRB was detected in a palm tree stump Waikoloa in October 2023 and a single CRB was found dead in a trap last month in that same area”, ag officials say.

From the Hawaiʻi Department of Agriculture:

The interim rule was signed today by HDOA Chairperson Sharon Hurd and is effective immediately. It is valid for one year, while HDOA finalizes a permanent rule which is slated to be considered by the Hawai‘i Board of Agriculture later this month.

Any individual, company, or organization that violates the rule will be charged with a misdemeanor and fined not less than $100 and up to $10,000. Penalties for a second offense committed within five years will require the violator to pay for the cost of clean-up and decontamination fees to remove contaminated materials, as well as the cost to fully eradicate any CRB infestations caused by the violation. Repeat violators will be fined not less than $500 and up to $25,000.

image from Hawaiʻi Department of Agriculture website

HDOA’s Plant Quarantine Branch inspectors at all island ports are concentrating efforts on inspections of potential CRB host material transported between islands.

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. An adult beetle is about two inches long, all black and has a single horn on its head. CRB grubs live in decomposing plant and animal waste. Adult CRB prefer to feed on coconut and other larger palms and are a major threat to the health of these plants.

Residents may go to the CRB Response website at: https://www.crbhawaii.org/ to learn more about how to detect the signs of CRB damage and how to identify CRB life stages. Reports of possible CRB infestation may also be made to the state’s toll-free Pest Hotline at 808-643-PEST (7378).

Surveillance for CRB has been ongoing on all neighbor islands, including pheromone traps at airports, harbors and other strategic locations. The traps are used for early detection of CRB infestations and are being monitored by HDOA, island Invasive Species Committees and the University of Hawai‘i.

The CRB is a large scarab beetle that was first detected on O‘ahu in 2013. The beetle has since been detected in many neighborhoods on O‘ahu, In May 2023, CRB was detected on Kaua‘i and collaborative eradication efforts continue on the island. On Hawai‘i Island, CRB was detected in a palm tree stump Waikoloa in October 2023 and a single CRB was found dead in a trap last month in that same area. CRB grubs were found in Kīhei, Maui, in November 2023, but have not been detected on the island since.

Photo of boring damage on palm trees, courtesy the Hawaiʻi Department of Agriculture

CRB is a serious pest of palm trees, primarily coconut palms, as the adult beetles bore into the crowns of the palms to feed on the trees’ sap. New unopened fronds are damaged in this way and when fully opened, may break and fall unexpectedly. If CRB kill or damage the growing point of the palm, the tree may die. Secondary fungal or bacterial pathogens may also attack the wounds caused by CRB, thereby killing the tree as well. Tree mortality after CRB attack has been reported to be anywhere from 10 percent to 50 percent. Dead trees then become a safety hazard as they may fall unexpectedly after the trunk rots, potentially resulting in bodily injury or property damage.

CRB is a major pest of palms in India, the Philippines, Palau, Fiji, Wallis and Futuna, Nukunono, American and Western Samoa and Guam. It is still not known exactly how the beetles arrived in Hawai‘i.