Microstructure and life cycle of Metisa plana Walker (Lepidoptera: Psychidae).

Abstract

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 1 st instar took 9 - 16 days to change into 2 nd instar. As the larva developed, it used lichen to build a case that it wore as it fed and grew. The development duration from 2 nd instar to 3 rd instar was 14 - 17 days. The 3 rd instar took the longest period at 16 - 18 days to develop into 4 th instar. Development of subsequent instar stages 4 th to 5 th and 5 th to 6 th were slightly shorter, between 10 - 15 days and 12 - 16 days respectively. In total, development of 1 st through 6 th instar stage of M. plana was 71.5 days.