Life table of pod borer, Helicoverpa armigera (Hubner) on pigeonpea

Life-table of H. armigera on pigeonpea was studied under laboratory condition. The output showed that out of total 100 eggs only the 89 eggs, 77 larvae and 70 pupae survived and finally emerged in to adults. The maximum durations of egg, larva, and pupa was 6, 20 and 8 days, respectively with pre-oviposition period varied from 33^rd to 35^th days of pivotal age. Female started laying eggs after 35^th days and ceased after 47^th days with lx (survival of female) values of 0.70 and 0.31 respectively. Females produced the maximum progenies (mx = 48.09) on the 38^th day of pivotal age. The net reproductive rate (Ro) was 142.07 times multiplication of population per generation. Adults contributed only 0.76 percent of the population of stable age whereas eggs, larvae, and pupae contributed 59.31, 37.68 and 2.26 per cent, respectively. The expectancy of further life was 4.76 days at the time of adult emergence which showed that life expectancy of H. armigera declined with the advancement of development.