Preferential Difference of Rhinoceros Beetle Incidence in Arecaceae Palms with Reference to their Chemical Composition

Rhinoceros beetle, Oryctes rhinoceros is the only major pest reported in all the oil palm growing states. The pest is a migrant from coconut to oil palm in the initial periods of establishment and later on changed its course of action by causing more incidence on coconut. The cellulose and lignin contents that are present in the leaf fibre are the critical factors for the pest attack with more incidence in more cellulose plants and vice versa. Feeding places played an important role in the per cent infestation. In case of coconut the pest is found to feed in the leaf silhouette where lignin content is less and cellulose content is more and hence the pest incidence is more. Where as in oil palm, the leaf petiole, which is the feeding place for the pest, is having more of lignin content and hence not preferred by the pest. Though the cellulose content is in general more in leaf fibre of oil palm, the petiole region is having more lignin and less cellulose and hence the differences in the pest attack between oil palm and coconut.