Population dynamics of leaf eating caterpillar, Spodoptera litura (fabricius) (lepidoptera: noctuidae) on castor

An experiment was carried out on population dynamics of leaf eating caterpillar, Spodoptera litura (Fabricius) on castor during 2009–10 and 2010–11 at Navsari Agricultural University, Navsari. The activity of pest commenced from 3^rd week of October and remained till 1^st week of April. The peak population was observed during first week of January. The population gradually decreased from 2^nd week of January. Minimum larval population was observed in 1^st week of April. The correlation coefficients (r) between pest population and maximum temperature (r=-0.714), minimum temperature (r=-0.814), average temperature (r=-0.911), morning relative humidity (r=-0.533), evening relative humidity (r=0.525), average relative humidity (r=-0.575), rainfall (r=-0.254) and evaporation (r=-0.601) were negatively significant.