Abstract:
Biological control of Oructes rhinoceros using entomopathogen is a promising alternative to the commonly used chemical control, as a part of the integrated pest management in oil palm plantations. The beetle breeds in rotting palm, wood stumps and empty fruit bunches in the field. It is not only a serious pest for young oil palms but for mature palms, especially in peat soil plantations. In some cases the entry hole of the pest on the crown can cause secondary fungy attacks, which cause spear-rot disease. Laboratory trials by Central Plantations Services (CPS) to investigate the growth rates and sporulation capacities of Metarhizium anisopliae showed that 12 days after inoculations, M. aniosoliae had grown fully in petridishes. It then sporulated profusely on corn media in 14 days post inoculation with a population of 2.7 x 109 spores/gram. O. rhinoceros beetle larvae werw obtained from the field and grown in non-sterile empty fruit bunch (EFB) composts, produced using aerated bunker composting anisopliae infected 97% of O.rhinoceros larvae within 14 days. Preliminary field trial was conducted ian a peat soil plantation with a heavy infestation of O.Rhinoceros beetless. The result showed that 88% larvae in the compost were infected within 35 days after treatment with M. anisopliae. The treatment was especially effective when larvae were in the 3rd instars stage. Research had shown that M.anisopliae was effective in controlling O.rhinoceros, our study si the first to show that the fungi can also be inoculated in the EFB compost. Despite their values as organic fertilisers, EFB compost are still not widely used, especially in peat soil plantations, mainly because O. rhinoceros beetles tend to breed in EFB compost. Here the study showed that compost can be used both as organic fertilisers and also as agents for pest control.
