Coconut Rhinoceros Beetle

REPORT IF SEEN: Report all suspect CRB or CRB palm damage to the Statewide Pest Hotline: (808) 643-PEST (7378)

Coconut Rhinoceros Beetle (CRB)

Species: Oryctes rhinoceros

KISC and partners are actively responding to the new CRB detection on Kauaʻi. Sightings of CRB or CRB palm damage should be reported immediately. If you suspect that you have CRB, KISC will survey and if confirmed, work with partners to control it for free.

The coconut rhinoceros beetle (CRB), Oryctes rhinoceros, was first detected on Kauaʻi in May 2023. This is the first detection in the State outside of Oʻahu.

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 various palm species that are foundational to cultural heritage, agriculture, ecosystems, and economies, when out of their native range.

Coconut Rhinoceros Beetle: black 2 inch beetle with horn — Coconut Rhinoceros Beetle

CRB Larvae stages 1 2 & 3 — Coconut Rhinoceros Beetle Larvae

Description

Adults

Adult CRB are black beetles about 2 inches in length
Native to Southeast Asia, first detected on Oʻahu in 2013
Both male and female beetles have a visible horn on thier head, though the male horn is usually larger
They are active at night and can fly.
Adult beetles live about 3-5 months
A female CRB lays an average of 90 eggs in her lifetime

Larvae

CRB eggs are layed and developed in mulch, compost, decomposing stumps or logs
Eggs hatch into “C” shaped, larval grubs and grow for 4-6 months reaching up to 3 inches before pupating.
As larvae, they live and feed on decomposing plant material.
CRB prefer coconut palm green waste but can survive in most decaying plant material.

Impacts

Adult CRB bore into the crowns of coconut palms to eat the developing leaves
CRB feed on and can kill coconut, royal, date, and fan palms
If these palms 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 creating 2 inch bore holes. Then, they use their sucking mouthparts to feed on the juices in the inner spear and heart.
CRB damaged palm fronds have distinct V-shaped cuts
The damage caused by CRB can kill the tree or leave it susceptible to disease
CRB threaten Kauaʻi’s endemic and endangered fan palms, Loulu
Grubs can spread through infested green waste, mulch, soil, and compost
Although CRB do not bite, they may carry diseases. CRB should not be handled with bare hands if possible

2" bore holes in palm fronds caused by CRB — 2″ bore holes caused by CRB

45 degree v-cuts on all the palm fronds of a coconut tree — 2″ bore holes caused by CRB

On Kauaʻi

In late May, 2 CRB were detected near the Lihue Airport by the green waste transfer station. KISC found both during routine monitoring of CRB traps placed for early detection around ports of entry as part of the Mamalu Poepoe program. This is the first detection of CRB outside of Oʻahu.

Response crews from the University of Hawaiʻi – CRB Response Team, KISC, HDOA, and other partners are surveying for possible breeding sites and suspect CRB palm damage island-wide. Additional monitoring traps have been placed at high-risk sites island-wide. 2 additional CRB have been captured in new traps deployed since the initial detection.

Detecting an infestation early increases our chances of eradicating CRB on Kauaʻi.

CRB beetle held in gloved hand — 1st CRB captured on Kauaʻi

Look-a-likes:

Oriental Flower Beetle: OFB

Protaetia orientalis, P. fusca

Oriental flower beetle or OFB is one of the most common look-alikes of the coconut rhinoceros beetle (CRB). Unlike CRB, OFB feed on overripe fruit, flower nectar, flower pollen, and sap from a variety of plants. They are a common widespread pest, with no control program.

Black Dung Beetle

Copris spp.

At first glance, dung beetles can look similar to CRB in that they are solid black and sometimes have an apparent horn. Dung beetles are significantly smaller than CRB reaching about 1.5 cm in length and have a rigid wing case.

Although dung beetles are not native, they are beneficial and were intentionally introduced to Hawaiʻi for the ranching and farming industry.

Queensland longhorn beetle

Acalolepta aesthetica

The Queensland longhorn beetle or QLB is a large invasive beetle established on the East side of Hawaiʻi Island. QLB is a major pest to tropical crops and should be reported immediately if found. For more information visit: https://www.biisc.org/qlb/