First coconut rhinoceros beetles found outside Waikōloa area on Big Island

The first coconut rhinoceros beetles have been found outside the Waikōloa area since the invasive insects were first detected a little more than a year ago on the Big Island.

A live adult coconut rhinoceros beetle was found March 3 at Ellison Onizuka Kona International Airport in Keāhole and another was discovered March 4 at Natural Energy Laboratory of Hawai‘i Authority in Kalaoa.

The invasive beetle at the Kona airport was found in a trap maintained by Big Island Invasive Species Committee during regular trap checks by committee team members as part of the interagency Ports of Entry/Exit Monitoring Program.

Formerly known as the Māmalu Poepoe Project, the Ports of Entry/Exit Monitoring Program is coordinated by Hawai‘i Invasive Species Council.

State Department of Agriculture, Big Island Invasive Species Committee, Hawai‘i Department of Health and Hawai‘i Ant Lab maintain traps for several invasive species at island ports, including airports, to support early detection of pests such as coconut rhinoceros beetles, Japanese beetles, Africanized honeybees, little fire ants and mosquito vectors of disease.

Big Island Invasive Species Committee has maintained traps since 2017 at the Kona airport as part of the program.

The beetle discovered at Natural Energy Laboratory of Hawai‘i Authority was found in a community hosted trap.

Both beetles were turned over to Hawai‘i Department of Agriculture officials.

Coconut rhinoceros beetle larvae were first discovered in October 2023 on the Big Island in the Waikōloa area, with several subsequent captures of adult beetles since but no further detections of larvae.

The total number of adult beetles found on the sland is now 7, with all previous finds having been in Waikōloa.

While they are the first coconut rhinoceros beetles found outside the Waikōloa area, it is unclear if the beetles are connected to that population or are new introductions via host material shipments from O‘ahu.

The invasive scarabs have become widespread on O‘ahu since first arriving there more than a decade ago in December 2013 at Joint Base Pearl Harbor-Hickam, and have devastated coconut palms.

Adult beetles lay eggs in decomposing plant material and are often found in mulch and soil.

Larvae develop within months and emerge as adults that then feed on the growing spear of palms. Coconut rhinoceros beetles also have been known to attack hala and banana.

Any coconut rhinoceros beetles found should be reported immediately to Big Island Invasive Species Committee or the local state Agriculture Department office. You can also find nearby drop-off locations online.

Big Island residents — especially those in the Waikōloa area and even greater West Hawai‘i region — should carefully check any purchases of mulch or soil, particularly local brands packaged on O‘ahu, for the presence of adult coconut rhinoceros beetles or their larvae.

Adult beetles can easily puncture the plastic wrapping and lay eggs inside, allowing for the development of larvae during and after shipment.

Sort through any host material you bring home and take pictures of any larvae. Send them to Big Island Invasive Species Committee via email at biisc@hawaii.edu, Instagram or Facebook to rule out look-alike species such as oriental flower beetle.

Keep any specimens found in case further investigation is necessary.

Waikōloa residents are encouraged to contact Big Island Invasive Species Committee and arrange for a backyard survey with a scent detection dog to locate any breeding populations of coconut rhinoceros beetles in the area.

Contact Big Island Invasive Species Committee at 808-933-3340 or via email at the address above for any further questions or additional information.