COCONUT RHINOCEROS BEETLE (CRB)

The coconut rhinoceros beetle (CRB), Oryctes rhinoceros, was first detected on O'ahu in December of 2013. Native to Southeast Asia, adult CRB feed on emerging palm fronds, causing damage that can often be severe enough to kill the plant.

 

CRB populations can have devastating impacts on palm species that are foundational to cultural heritage, agriculture, ecosystems, and economies, when out of their native range. 

IDENTIFICATION

Adult male coconut rhinoceros beetle with a transparent background to demonstrate 2" length

~2 inches

Adults

Adult coconut rhinoceros beetle (CRB) are black beetles averaging 2 inches in length with a visible horn. They are night-active and can fly. Although they do not bite, they may carry diseases, so they should not be handled with bare hands if possible.

Larvae

CRB larvae can grow up to three inches before pupating. These larvae crawl on their side and curl into a "C" shape when handled. As larvae, they live and feed on decomposing plant material. CRB prefer coconut palm green waste but can survive in most decaying plant material.

Coconut rhinoceros beetle life stages observed at 30 degrees Celsius. CRB breeding sites are typically established in decaying plant material like mulch, compost, decomposing stumps, or felled trees. After hatching from eggs, larvae begin feeding on the decomposing material. After growing through three larval stages, called instars, larvae pupate and emerge as an adult, leaving the breeding site. CRB spend roughly 3.5 months growing from an egg to an adult, and about 3 months as an adult. 

CURRENT STATUS

April - Sept. 2021

Coconut rhinoceros beetle detections have increased in the last 6 months. High-catch areas continue to be Pearl City Peninsula, Waipiʻo Peninsula, West Loch, ʻEwa Beach and Central Oʻahu. We're seeing regular finds on the West Side of Oʻahu and concerning spread into the North Shore. The CRB Response is identifying CRB breeding sites, treating infested material, and providing tools for community members to minimize their risk.

TrapHitsAprilSept.PNG

HISTORICAL CONTEXT

Although native to Southeast Asia, the distribution of CRB today includes many Pacific Islands, including O'ahu. To date, CRB has not been reported on any other Hawaiian islands, the mainland United States, Central America, or South America, but any tropical ecosystem that produces host species for the CRB is at risk of infestation.

CRB was discovered at Mamala Bay, O'ahu December 2013. It is assumed the beetle came from Guam, as genetic testing has shown similarities between the beetles found in both places, although we do not know how it arrived. While it was first detected at the airport (HNL), there are both military and commercial flights from areas with CRB populations.

 

CRB DAMAGE

CRB feed on and damage coconut, royal, date, and fan palms. If these preferred food sources are unavailable, CRB can host shift to feed on other palms and tropical crops. CRB use their front legs and horn to dig into the crown of trees. Then, they use their sucking mouthparts to feed on the juices in the inner spear. 

REPORT