Pusat Sistematik Serangga, Universiti Kebangsaan Malaysia
Abstract
The outbreak of bagworm has been a severe threat, causing significant loss to the oil palm
industry in Johor, Malaysia. This study investigated the impact of multiple aerial applications
of Bacillus thuringiensis (Bt)-based biopesticides in controlling the bagworm outbreak at two
smallholdings in Johor, namely Smallholding A (Sh.A) and Smallholding B (Sh.B). Two types
of agricultural aircrafts used in this study were Grumman G-164 A Super AgCat and M-18
Dromader. The results showed that a significant reduction of bagworms (83.5%) was recorded
after the third round of aerial spray in Sh.A. Whilst, Sh.B recorded a significant reduction of
bagworms (83.5%) after the fourth round of aerial spray. The result indicated that multiple
applications of Bt aerial spray at the precise timing and strategy based on the bagworm’s life
cycle are crucial in ensuring the application’s effectiveness in bringing down the bagworm
population to below the economic threshold level (ETL). A census conducted in 2019 and 2020
recorded that the bagworm population in both areas maintained below the threshold level even
after more than three years of application. With the implementation of a long-term Integrated
Pest Management (IPM) strategy, such as planting beneficial plants, the bagworm population
can be maintained under ETL even after years of aerial sprays