The Marshall Islands versus the Coconut Rhinoceros Beetle

21/06/2024

In the Marshall Islands, where the Pacific Ocean's vibrant turquoise waters meet scattered atolls, the coconut palm stands majestically as both a vital emblem of sustenance and a profound cultural symbol.

Known affectionately as "the tree of life," the coconut palm is deeply integrated into the Marshallese way of life, inspiring legends and serving a variety of practical purposes.

One such legend recounts the story of a massive coconut tree that emerged from the grave of a revered chief. It is said that its fronds stretched toward the heavens while its roots extended deep into the underworld, symbolizing a sacred bridge between the spiritual and human realms.

This tale exemplifies the deep spiritual connection the Marshallese people have with nature.

In daily life, every part of the palm is used with great respect: fronds are woven into thatched roofs and mats; trunks are fashioned into durable canoes, and the coconuts themselves provide essential nourishment.

Beyond these uses, the tree symbolizes resilience and continuity, reminding the community of the interconnectedness of life.

However, this critical cultural and ecological staple is now threatened by the Coconut Rhinoceros Beetle (Oryctes rhinoceros). Originally native to Asian countries, this pest has found its way to various parts of the Pacific, posing significant threats to local agriculture and ecosystems.

The Food and Agriculture Organization of the United Nations (FAO) has responded by assessing the beetle's impact and spearheading strategic interventions to control its spread. 

Adult rhinoceros beetles, distinguishable by the prominent horn on males used in mating battles, can measure between 35 to 50 millimetres in length.

At first, the pest was detected in the vicinity of Amata Kabua International Airport, located in the western part of Rairok on the south side of the atoll of Majuro, the capital of the Republic of the Marshall Islands. The discovery was deemed so dangerous that the Government of the Marshall Islands declared a state of emergency in the country on 2 October 2023.

The life cycle of the rhinoceros beetle involves complete metamorphosis, progressing from egg to larva, to pupa and then to an adult beetle. Females lay eggs in decaying organic debris such as coconut logs and leaf piles, where the larvae—creamy white grubs with brown heads—feed and grow, potentially reaching up to 60 millimetres in length.

This stage can last several months, depending on environmental conditions, before they pupate in earthen cells and emerge as adults in 20-25 days.

The adult beetles are particularly destructive as they burrow into unopened palm fronds to feed on essential tissues, causing damage to the spathes, which leads to loss of nut clusters. This damage reduces the yield of coconuts, which are crucial exports for the islands, valued at approximately USD 15 million annually and predominantly produced by smallholder farmers.

Given that coconut cultivation covers most of the land across the islands—except for the more urbanized atolls—the beetle infestation is not merely an agricultural issue but a crisis threatening the foundation of island culture.

FAO's Integrated Pest Management approach reduces reliance on pesticides, which can exacerbate pest issues and pose risks to environmental and human health. FAO trained local plant protection officers to enhance the country’s capacity to effectively manage this pest. © Oscar from Pixabay

At the request of the government, FAO led the efforts to manage these pests and control their spread. These efforts include sanitizing affected trees and implementing integrated pest management (IPM) solutions, specifically tailored to meet the islands' unique needs.

Shoki AlDobai, FAO’s Team Leader for Locusts and Transboundary Plant Pests and Diseases, emphasized the critical nature of these measures, stating, "The urgent support is aimed at protecting the vital coconut resources and the well-being of the island communities and at strengthening the government's response to the rhinoceros beetle outbreak."

The FAO's broader IPM strategy aims to reduce reliance on pesticides, which can exacerbate pest issues and pose risks to environmental and human health.

This approach balances pests and their natural enemies, integrating biological, physical and cultural strategies to cultivate healthy crops and minimize pesticide use. The goal is to promote a sustainable ecosystem approach, encouraging natural pest control mechanisms and fostering the growth of resilient crops, avoiding chemical methods as much as possible.

Maged Elkahky, FAO Agricultural Officer working on Locusts and Transboundary Plant Pests and Diseases, also highlighted the importance of enforcement of the phytosanitary measures, raising awareness and the regular monitoring of transboundary plant pests such as CRB to prevent their introduction. The early detection of CRB and similar pests allows for early action and enhances the chances of containment and even potential eradication.  

To enhance local capacity to effectively manage this pest, training sessions for Field and Plant Protection Officers have been crucial. Moreover, a national action plan has been developed to improve surveillance and coordination among stakeholders, preventing the beetle’s spread to new areas and raising awareness about effective pest management strategies across all islands.

Hemant Nitturkar, FAO Agriculture Officer in Samoa, stressed the importance of heightening community awareness and participation in preventing, containing and managing transboundary pests along with promoting accessible and context-appropriate technologies.

This coordinated effort has successfully limited the presence of the pest to the atoll of Majuro, reflecting a dynamic process rooted in ecological principles. It aims to sustain ecosystem functions while safeguarding the Marshallese heritage and their cherished "tree of life."

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