Moringa oleifera Lam. is widely grown in Sri Lanka. In recent years, a seasonal pest Noorda blitealis Wlk. turned into a major pest on Periyakulam 1 (PKM 1) annual Moringa in Jaffna district. A study was carried out to record the biological and morphological characters of N. blitealis on PKM1 Moringa under Sri Lankan climatic condition. Larvae were collected from the affected areas and reared in the laboratory. N. blitealis females laid oval and creamy eggs in clusters which had an incubation period of 2.2 ± 0.4 days with 80.4% of hatchability. The larvae were transparent to creamy, light green and became pink at the final stage with a body length of 2-20 mm. Five instars were determined using Dyar’s rule. At the each moult, the mean growth ratio of head capsule width was 1.54. The larval period was 9 to 11 days. The period of first, second, third, fourth and fifth instar was 1.3±0.1, 2.0±0.6, 2.1± 0.5, 2.45±0.6 and 2.2±0.4 days, respectively. The obtect pupa was dark brown, 8.4±0.5mm long and the mean pupal period was 7±0.92 days. The adult emergence was 67.79±5.33%. Moths were small with dark brown abdomen. The female and male adult longevity were 10.35±2.08 and 7.11±2.85 days, respectively. The male: female sex ratio was 1: 1.3.