Life fecundity table of Maruca vitrata on green gram

Abstract

The studies on life fecundity table, age specific distribution and life expectancy of Maruca vitrata (Geyer) on green gram cv. Meha were carried out at a constant temperature of 26 + 1 0C during the month of July to October, 2013 at Anand Agricultural University, Anand (Gujarat). Pre-oviposition period was 22 and 23 days of pivotal age. Female started laying eggs after 23rd day and stopped after 34th day with lx values being 0.59 and 0.03, respectively. The females contributed the highest number of progeny (mx= 25.12) on 27th day of pivotal age, which decreased day by day. The net reproductive rate (Ro) of 62.91 was obtained with a mean length of generation (Tc) 27.03 days. Intrinsic rate of natural increase in number (rm) was 0.1551 females per female per day and the population would be able to multiply 2.36 times per week. The hypothetical F2 females were worked out to be 3957.67. The life expectancy of M. vitrata declined gradually with the advancement of development. The life expectancy of newly deposited eggs was 7.48 days. The expectancy of further life was 2.80 day at the time of adult emergence. The contribution of egg to stable age distribution was 54.42 per cent, whereas it was 41.61 per cent by larval stage. Contribution of pupal and adult stage was negligible as it found 2.51 and 1.46 per cent, respectively.