Maximum Activity of Heliothis armigera (Hb), Earias vittella (F.) and Pectinophora gossypiella Saunders during November-January, October-January and October-April, respectively was noticed at the Regional Research Station, Raichur, during 1987-88. The relationship of pheromone trap catches of all three species of cotton bollworms was negative and not significant with rainfall, negative and significant with average maximum and average minimum temperatures, positive and significant with average morning relative humidity in the case of H, armigera and P. gossypiella and positive and non-significant with average afternoon relative humidity. The regression analysis suggested that all the weather parameters together influenced significantly the catches of all the three species of bollworms