Oryctes rhinoceros is an important pest attacking young oil palms in South-east Asia. In Malaysia, in addition to well-known breeding sites it is able to multiply in shredded chipped old oil palm trunk material in replant areas, also in empty fruit bunches. The aggregation pheromone ethyl 4-methyloctanoate is produced by males of O. rhinoceros (also by the similar pest O. monoceros in Africa), and is used in traps as an important component of Integrated Pest Management (IPM) and in ecological studies. In Malaysia, the incidence of endemic entomopathogens can be increased. The fungus Metarhizium anisopliae is available for use as a biopesticide against immature stages in breeding sites and may be distributed by adults. The molecular and ultrastructure of Oryctes Nudivirus (OrNV) has been extensively studied. It kills larvae and is disseminated by adults. New PCR techniques may enable reliable estimates of the quantity of virions in experimental dosages ingested and hence of the virulence of different isolates. It is possible one isolate when released may out compete another.12 page(s