Oryctes rhinoceros (Coleoptera: Scarabaeidae) as a key pest of oil palm: a systematic review of its biology, establishment, and integrated management strategies in Malaysia

Oryctes rhinoceros (coconut rhinoceros beetle) is a major pest of oil palm in Malaysia, with its impact intensified under zero-burn replanting systems that create persistent breeding sites. The emergence of the CRB-G (Guam) haplotype, which exhibits reduced susceptibility to Oryctes rhinoceros nudivirus (OrNV), has further compromised conventional biological control strategies, highlighting the need for updated management approaches. This study presents a PRISMA-compliant systematic review, complemented by exploratory bibliometric analysis, to synthesize evidence on the biology, establishment, and management of O. rhinoceros in Malaysia. Literature published between 1970 and 2025 was retrieved from major scientific databases using predefined PICOS criteria, yielding 14 studies eligible for qualitative synthesis. The review indicates that residue-intensive replanting practices significantly enhance beetle population persistence, whereas biological control measures, particularly Metarhizium anisopliae-based formulations, demonstrate more consistent field efficacy against CRB-G populations than OrNV alone. Pheromone trapping remains an effective tool for monitoring and population suppression when integrated within comprehensive integrated pest management (IPM) programs, while chemical control is increasingly limited by environmental and sustainability concerns. Bibliometric trends reveal a progressive research shift from chemical-based interventions toward biological, molecular, and sustainable IPM strategies. This review consolidates current knowledge, identifies critical gaps regarding CRB-G adaptation, and outlines priorities for developing resilient, sustainable management strategies in Malaysian oil palm systems.