Journal of Oil Palm Research Vol. 23 (2) August 2011, p. 1096-1109 RAMLE Moslim * ; NORMAN Kamarudin * ; IDRIS A Ghani ** ; MOHD BASRI Wahid * ; JACKSON, Trevor A † ; TEY, C.C. †† ; MOHD AHDLY ††*
The successful introduction of the Oryctes rhinoceros virus to control an outbreak of the rhinoceros beetle, O. rhinoceros on coconut in the South Pacific islands has led MPOB to embark on a project to study the potential use of the virus in oil palm plantations in Malaysia. Two DNA-based technologies, the polymerase chain reaction (PCR) and the restriction virus genome by an endonuclease enzyme, have been developed and intensively used in the project. PCR is a sensitive yet simple procedure allowing a more accurate estimation of the infection level of the O. rhinocerosvirus on adult beetles and larvae. PCR diagnosis showed that the adult beetles were more commonly infected (30%-65%) as compared with larvae (0%-35%). Pre-pupae and pupae were free from the virus infection. Virus genomic analysis by an endonuclease enzyme HindIII identified four types of O. rhinoceros virus, named as type A, B, C and D. Bioassays showed that the virus type B was more pathogenic against the third instar larvae and neonates. A virus field introduction system was then established. The virus solution was produced by an in vivo method using the larvae and adult beetles. Introduction of the O. rhinoceros virus type B in an estate with palms less than one year old with existing virus of type A resulted in a successful reduction of the adult population as well as in palm damage. The released virus established as early as three months after release (MAR) and persisted up to 15 MAR. The virus type B was then introduced in an immature area with palms more than three years old. The virus infection gradually increased and was maintained at a higher level of between 60% and 90%. The adult population was reduced, and stayed at a low level for a certain period of time before slowly increasing again to reach a second peak. The virus infection had a weak negative correlation with the adult population. A slow reduction in the proportion of males was observed, possibly due to slow virus transmission, as the adult population had probably already adapted to the virus infection. Genomic analysis showed that the virus type B was detected only at four MAR. Factors ensuring the success of virus transmission in the population were elaborated upon. Further research to fully utilise the O. rhinoceros virus to ensure maximum control of the rhinoceros beetle was also discussed.KEYWORDS:
* Malaysian Palm Oil Board, P. O. Box 10620,
50720 Kuala Lumpur, Malaysia.
** School of Environmental and Natural Resources Science,
Faculty of Science and Technology, 43600 UKM Bangi,
† AgResearch, Lincoln Research Centre,
Private Bag 4749, Christchurch 8140, New Zealand.
† † Sime Darby R&D Centre, P. O. Box 207,
42700 Banting, Selangor, Malaysia.