LIFE-TABLE PARAMETERS OF FRUIT BORER, HELICOVERPA ARMIGERA (HUBNER) HARDWICK IN TOMATO, LYCOPERSICON ESCULENTUM ESCULENTUM ESCULENTUM MILL

Abstract

Pre-oviposition period of H. armigera was at 44th and 45th day of pivotal age. Female started laying eggs after 45th day and stopped it after 54th day, with lx values being 0.71 and 0.11, respectively. The females contributed the highest (mx = 45.55) number of progeny on 50th day of pivotal age. The net reproductive rate (Ro) was 160.53 obtained with a mean length of generation (Tc) 49.03 days. The intrinsic rate of natural increase in number (rm) was 0.1045 females per female per day with finite rate of increase of 1.34 females/ female/ day and the population would be able to multiply 8.60 times per week. The hypothetical F2 females were worked out to be 25769.88. Adults contributed only 0.06 per cent to the population of stable age and that of eggs, larvae and pupae were 69.32, 30.23 and 0.39 per cent, respectively. The life expectancy of newly deposited eggs was 14.07 days. The expectancy of further life was 2.83 days at the time of adult emergence which clearly indicated that life expectancy of H. armigera declined gradually with the advancement of development.