author(s)
T Boopathi, SB Singh, T Manju, SK Dutta, AR Singh, Y Ramakrishna, S Chowdhury, Lungmuana, V Dayal and S Saha

abstract
The present investigation was undertaken to know the impact of abiotic factors on the population fluctuation of Melanitis leda ismene (Cramer) (Lepidoptera: Satyridae) and Cnaphalocrocis medinalis (Guenee) (Lepidoptera: Pyralidae) in rice agro-ecosystem under rain fed low land conditions in Mizoram, India during Kharif season in both 2013 and 2014. Results showed that C. medinalis were the first to attack the crop during last week of August, whereas M. leda ismene was recorded during second week of September i.e., 37^th SMW. The incidences of C. medinalis and M. leda ismene varied due to season. The highest incidences of C. medinalis (6.8/10plants) and M. leda ismene (16.3/10plants) were found during September. Minimum temperature and rainfall showed significant correlation with incidecnes of C. medinalis and M. leda ismene. During the pooled year when there was abrupt fall in morning RH, rainfall and rainy days a build-up in M. leda ismene incidence was observed. When there was increase in morning RH and rainfall a build-up in C. medinalis incidence was recorded. These studies clearly indicate that weather factors play a vital role in C. medinalis and M. leda ismene incidence, which is essential for development of management strategies.