Isolation and amplification baculovirus as a biocontrol agent for bagworms and nettle caterpillars of palm oil

Outbreaks of bagworms (Lepidoptera: Psychidae) and nettle caterpillars (Lepidoptera: Limacodidae) in oil palm occasionally affects some estates in Malaysia. Control involves mainly the use of systematic chemicals such as monocrotophos and methamidophos and the spraying of selective narrow spectrum insecticide such as triclorfon. Chemical insecticides pose several potential hazards such as residual problem, insect pest resistance to chemicals and increased frequency of pest outbreaks. In the 1991 national biological control conference, integration of selective chemicals with biological control was recommended as a strategy towards non-polluting agriculture in Malaysia. Use of baculovirus (BV) as a biological control agent supports this recommendation. The objective of this study is to report the progress made in collection, isolation and amplification of BV for the control of some oil palm insect pests. Collection of 62,000 larvae of Metisa plana, Wlk (Lepidoptera: Psychidae) and 1,000 other pests were in 1992-1995 from 20 estates in Selangor, Johor, Negeri Sembilan, Pahang, Sabah and Perak. The larvae were dissected, treated and examined for BV infection, particularly the subgroup A and B. The results indicated that nucleopolyhedrosis virus (NPV) was detected in M. plana, but the degree of infection was tertiary, meaning that it did not successfully infect the host. Granulosis viruses (GV) were detected more frequently than the NPV. Detection of BV was enhanced in stressed and newly dead larvae. To date Mahasena corbetti NPV (McNPV), Darna trima GV (DtGV), Spodoptera litura NPV (SlNPV), Mamestra brassicae NPV (MbNPV), Agrotis segetum NPV (AsNPV), A. segetum GV (AsGV), Autographa californica NPV (AcNPV) (L1, 210, 449) and Panolis flammae NPV (PfNPV) have been purified. Mass production of BV for field experiment has been done by in vivo amplification using a susceptible host. Studies on amplification of these viruses in an alternative host, S. litura was carried out. The amplified viruses will be used for characterization and cross-infectivity studies against oil palm insect pests.