A Maui arborist found 17 live coconut rhinoceros beetles while cutting down coconut palm trees in Kihei on Tuesday.

What You Need To Know

  • The arborist was contracted to remove a dozen dead palm trees and found the larvae in the crown of the first tree he cut

  • Seven of the larvae were transported to Oahu for identification and have been confirmed as CRB by a state entomologist

  • All coconut material from the 12 trees were chipped, contained in a 20-foot container and fumigated to kill any larvae or possible CRB eggs

  • Surveillance for CRB has been ongoing on all neighbor islands and thousands of pheromone traps have been deployed at airports, harbors and other strategic locations

The arborist was contracted to remove a dozen dead palm trees and found the larvae in the crown of the first tree he cut. He sent photos to the Maui Invasive Species Committee, which shared the photos with the state Department of Agriculture’s Maui Plant Pest Control Branch. Personnel from both agencies drove to the site near Lipoa Parkway to investigate.

The arborist and his crew cut down the remaining palms but found no additional beetles or larvae.

Seven of the larvae were transported to Oahu for identification and have been confirmed as CRB by a state entomologist. 

All coconut material from the 12 trees was chipped, contained in a 20-foot container and fumigated to kill any larvae or possible CRB eggs. HDOA and MISC staff will continue to conduct surveys in the area, and any suspect palms will be removed. HDOA staff are also deploying additional CRB pheromone traps to detect adult CRB populations in the area.

“The Department of Agriculture staff on Maui have been working in earnest to stop the spread of the coconut rhinoceros beetle and will continue to intensify efforts to detect and manage any infestations,” said Hawaii Board of Agriculture chair Sharon Hurd. “We’re up against a formidable enemy, as well as many other pests, and will do the best that we can with existing resources and through collaboration with our partners.” 

In September, HDOA personnel found a dead adult CRB on Maui in a compost bag at a Maui big-box store during a routine survey. This was the first CRB detection on the island, but it is not believed to be related to the larvae found in Kihei. 

Following the initial discovery, HDOA’s Plant Quarantine Branch inspectors increased inspections and surveillance on CRB host material, sifting through commercial compost piles and inspecting pallets of bagged compost arriving on Maui.

Green waste provides an optimal breeding environment for CRB, and residents on all islands are urged to check their compost bins, mulch piles and green waste for CRB larvae, according to HDOA.

An interim rule restricting the movement of CRB host material from Oahu to neighbor islands is in place. CRB host material includes but is not limited to palm plants; decomposing plant material such as compost, wood or tree chips, and mulch; plant-growing media (potting soils, etc.); and other organic plant material products.

CRB was first detected in the state in December 2013 on Oahu and has gradually spread from Central and West Oahu to the North Shore and the windward side.

In May, a live beetle was detected in a trap on Kauai by a survey crew from the Kauai Invasive Species Committee. As of Oct. 31, 41 CRB adults and nine larvae have been detected on Kauai. Efforts on the island to detect and eradicate CRB are ongoing, with the help of the KISC and the County of Kauai. 

Surveillance for CRB has been ongoing on all neighbor islands, and thousands of pheromone traps have been deployed at airports, harbors and other strategic locations. The traps are used for early detection of CRB infestations. 

CRB is a serious threat to palm trees, primarily coconut palms, as adult beetles bore into the crowns of the palms to feed on the tree’s sap. New unopened fronds are damaged 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. Tree mortality after a CRB attack has been reported to be anywhere from 10% to 50%. Dead trees may fall unexpectedly after the trunk rots, potentially resulting in bodily injury or property damage.  

The beetle can be found in India, the Philippines, Palau, Fiji, Wallis, Nukunono, American and Western Samoa and Guam. It is not known how the beetles arrived in Hawaii.

Reports of possible CRB infestation may be directed to the CRB Response Team at (808) 679-5244 or email info@crbhawaii.orgor the state’s toll-free Pest Hotline at (808) 643-PEST (7378).