Effect of different temperature on survival rate and life cycle of oil palm bagworm, Metisa plana (lepidoptera: psychidae) under controlled condition / Cynthia Eja Enting

Temperature is one of the most important abiotic factors that affects insect life cycle. Unpredictable local climate changes in Malaysia had caused the outbreak of bagworm, Metisa plana for over five decades. This had led to a major problem of oil palm yield production. Hence, it is significant to study the nature of this pest especially their life cycle to prevent further outbreak. This study is expected to provide M. plana surveillance program planning that can prevent massive damage of defoliation from occurring. The application to control bagworm should be applied at the right time especially during the crucial climate changes that could triggers bagworm's life cycle. The main objective in this study is to evaluate the life cycle of oil palm bagworm, M. plana in different degree of temperature. The ranges of temperature selected were between 16°C to 40°C. This study was conducted under controlled conditions in the laboratory from October 2017 until October 2018. The study was done by daily observation and recorded the duration in days from egg to adult stages. This study found that bagworm was able to adapt and complete life cycles at selected temperatures between 20°C to 36°C, but did not survive at 16°C and 40°C. The duration observed the completed life cycle of this species significantly decreased with increase in temperature. The duration in days of completed life cycle of temperature at 20, 24, 27.5, 32 and 36 °C was approximately 122.2±0.87, 108.4±1.74, 99.6±1.89, 81.2±1.70 and 64.8±1.25 respectively. The optimum temperature of the bagworm's survival rate was 32°C with a total percentage of 63.48%. This study provides basic fundamental information on the life cycle of bagworm, Metisa plana especially for oil palm growers. Hence, growers will have better pest management plans to control this bagworm species and prevent yield loss of fresh fruit bunch (FBB) of oil palm plantation per acre. This recent knowledge of biology in the life cycle of Metisa plana should be done at least every six to seven years. It is expected that this study could provide Metisa plana surveillance program planning that can prevent massive damage of defoliation from occurring.