MICROSTRUCTURE AND LIFE CYCLE OF METISA PLANA WALKER (LEPIDOPTERA: PSYCHIDAE)

The Metisa plana (Lepidoptera: Psychidae), is an important defoliator of oil palm in Southeast Asia. Severe defoliation on palm consequently affects the productivity. The rearing protocol, microstructure, behaviour and life cycle of all stages of M. plana are described. The life cycle of M. plana from egg to adult in this controlled rearing environment was 103.5 days. The larvae of M. plana in this study undergo six larval instars. The larva started feeding immediately upon being laid on the leaf surface. In the larval period, the 1st instar took 9 – 16 days to change into 2nd instar. As the larva developed, it used lichen to build a case that it wore as it fed and grew. The development duration from 2nd instar to 3rd instar was 14 – 17 days. The 3rd instar took the longest period at 16 – 18 days to develop into 4th instar. Development of subsequent instar stages 4th to 5th and 5th to 6th were slightly shorter, between 10 – 15 days and 12 – 16 days respectively. In total, development of 1st through 6th instar stage of M. plana was 71.5 days.