Relationship between Bagworm and predatory insect species in oil plantations of Peninsular Malaysia

Abstract

Bagworm, Metisa plana Walker (Lepidoptera:Psychidae) is one of the most destructive pests in Peninsular Malaysia's oil palm plantations. Trials were conducted in the Kuala Selangor, Selangor and Kemayan, Pahang Region, Malaysia. The aim of the present study was to assess the effects of three different management regimes (Fully-adopted planting technology of beneficial plants, single planting beneficial plants and without beneficial plants) on Bagworms and predatory insects in oil palm plantation. We investigated the relationship between species richness of predatory insects and Bagworm infestation. During the study period 2,710 and 4,564 individuals larvae and Pupa M. plana respectively were recorded. We also recorded 1,035 individuals from two species of predatory insects. The findings showed Bagworms and Predators populations were not correlated with weather parameters. Our study revealed the abundance of Predators is dependant to host population of the Bagworms. Due to the negligible numbers of bagworms host in sites, the activities of Insect Predators shifted mainly to T. Subulata plants along the roadside. Our results indicated that the abundances of C. Picticeps and S. Dichotomus increased with the richness of beneficial plants. To maintain predatory populations at high number, planting beneficial plants in oil palm plantation should be priortized by stakeholders.