Coconut Rhinoceros Beetle in Samoa: Review of a Century-Old Invasion and Prospects for Control in a Changing Future

Abstract

It is now more than 100 years since the coconut rhinoceros beetle (CRB: Oryctes rhinoceros L.) was first detected in the Pacific Island state of Samoa. The exotic pest from Asia became the principal pest of coconut palms in Samoa and, from this first point of invasion, spread to several surrounding countries in the South-West Pacific Ocean. An intensive control operation was initiated, but the beetle could not be eliminated. Various pest management strategies were attempted but had limited success until the introduction of a biological control agent (BCA), Oryctes rhinoceros nudivirus (OrNV), during the late 1960s and early 1970s. The biocontrol release was very successful and became the prime example of “classical biological control” of an insect pest by a virus. Changing economic and social conditions in Samoa and other islands of the Pacific require a re-evaluation of the threat of CRB to coconut production to suggest how the IPM system may be modified to meet future needs. Therefore, it is timely to review the history of CRB in Samoa and summarize experiences in development of an integrated pest management (IPM) system limiting the impact of the pest. We also present results from a recent study conducted in 2020 on the island of Upolu to define the current status of the CRB population and its BCA, OrNV. The lessons from Samoa, with its long history of containment and management of CRB, are applicable to more recent invasion sites. Recommendations are provided to modify the IPM programme to enhance the sustainable control of CRB and support the ongoing coconut replantation program promoted by the Samoan government.

Tracking potential biosecurity incursions using publicly available images: A case of coconut rhinoceros beetle

“…The coconut rhinoceros beetle, Oryctes rhinoceros (L.), (CRB) was endemic to South/South East Asia, but has spread to islands in the Pacific and Indian oceans during the last 100 years (Catley, 1969; Marshall et al, 2017; Paudel et al, 2022). A possible establishment of CRB in the western hemisphere was also recently reported (Jackson et al, 2022).…”

“…Unlike human and animal diseases, the effects of plant pests are usually recognized after a significant spread with visible damage in large areas of crops and trees.Early detection and surveillance of plant pests of biosecurity risk are largely dependent on trapping and in-person inspections, which are labour intensive and expensive. Early detection of pests is essential for effective management or eradication, therefore, there is need for efficient and inexpensive surveillance methods for pest biosecurity, particularly for resource-poor countries in the global South.The coconut rhinoceros beetle, Oryctes rhinoceros (L.), (CRB) was endemic to South/South East Asia, but has spread to islands in the Pacific and Indian oceans during the last 100 years (Catley, 1969;Marshall et al, 2017;Paudel et al, 2022). A possible establishment of CRB in the western hemisphere was also recently reported (Jackson et al, 2022).…”

Social media posts suggest that coconut rhinoceros beetle has established in the Western hemisphere

“…The adult beetles feed by boring through the developing leaf tissue at the crown of the palm leaving distinctive v‐cuts as the fronds emerge, characteristic of CRB attack (Figure 1). CRB first entered the Pacific through importation of potted rubber seedlings from South Asia at the start of the 20th century (Paudel et al, 2022) and remains one of the major pests of coconut and oil palms in the region.…”

“…The adult beetles feed by boring through the developing leaf tissue at the crown of the palm leaving distinctive v-cuts as the fronds emerge, characteristic of CRB attack (Figure 1). CRB first entered the Pacific through importation of potted rubber seedlings from South Asia at the start of the 20th century (Paudel et al, 2022) and remains one of the major pests of coconut and oil palms in the region.The coconut rhinoceros beetle has coevolved with palms and is currently spreading through the palm growing areas of the Asia and many Pacific islands. The pest was recently reported from the Pacific islands of Guam and Hawaii causing concern that it could reach the Americas (Jackson, 2015).…”

Social media posts suggest that coconut rhinoceros beetle has established in the Western Hemisphere

“…The adult beetles feed on the developing leaf tissue at the crown of the palm leaving distinctive v-cuts as the fronds emerge, characteristic of CRB attack. CRB first entered the Pacific through importation of plants from Southeast Asia at the start of the 20 th century (Paudel et al, 2022) and remains one of the major pests of coconut and oil palms in the region. CRB has coevolved with palms and is currently spreading through the palm growing areas of Asia and many Pacific islands.…”