Detection of coconut rhinoceros beetle on Maui underscores need for proactive efforts

The recent finding of a dead coconut rhinoceros beetle on Maui has prompted calls for vigilance among contractors and landowners to prevent the accidental spread of invasive species.

The Coordinating Group on Alien Pest Species, program staff from the Hawaiʻi Invasive Species Council, and the five Invasive Species Committees in Hawaiʻi are urging extra caution in light of the finding.

To support these efforts, the Coordinating Group on Alien Pest Species, Hawaiʻi Invasive Species Council support staff, and the Invasive Species Committees have compiled a list of best management practices for coconut rhinoceros beetle (CRB), little fire ants, and other species. 

This appeal comes at a time when the urgent need to address impacts from the Maui fires may increase the introduction of infested materials from off island.

The proposed reissuance of an emergency quarantine measure, Plant Quarantine Interim Rule 22-1, which restricts the movement of mulch and other potential CRB host materials from Oʻahu, is an important step, but by itself will not be adequate to the spread of this harmful pest. Contractors and individuals need to be sure that pests are not unwittingly moved in palm trees, green waste, mulch, loose or bagged compost, bagged soils, and similar items.

Throughout the state, the continued spread of pests poses significant risks: 

• Kauaʻi: The recent arrival of the coconut rhinoceros beetle pest to Kaua’i (detected May 31, 2023) highlights the threat posed by the movement of infested material. A decade of research on controlling the pest could lead to eradication on Kaua’i, but limiting the human-vectored spread is critical to achieving this goal.  
• O’ahu: Continued human-vectored spread will exacerbate the challenges in addressing this pest. 
• Maui County: with the increased volume of material moved to and around Maui to help with fire recovery efforts (including mulch and imported coconut coir, mulch, or greenwaste for use in erosion control sock filler), mulch and compost for restoring burn scars, and plants for restoration, there’s an increased risk of introducing invasive species. 
• Hawai’i Island: To date, CRB have not been detected on Hawai’i Island. Should they arrive, they would likely spread quickly, given the low population density and plentiful habitat that could lead to challenges in detecting and eradicating the pest. 

The best management practices highlight practices to prevent the spread of coconut rhinoceros beetles, but also provide general guidelines for little fire ants, coqui frogs, two-lined spittle bug, and other invasive species. 

For restoration projects, the best management practices provide guidance on fire risk assessments and non-invasive characteristics for selecting plants.  

For more information:

• List of Best Management Practices: https://dlnr.hawaii.gov/hisc/files/2023/09/BMPs-for-Invasive-Species-Prevention-091223.pdf
• Christy Martin, Coordinating Group on Alien Pest Species, christym@rocketmail.com
• Coconut Rhinoceros Beetle Response: 808-679-5244, info@crbhawaii.org
• Island-based Invasive Species Committees: https://www.hawaiiinvasivespecies.org/
• Pacific Fire Exchange: Melissa Chimera, melissa@hawaiiwildfire.org