Biology and life-fecundity table of invasive fall armyworm, Spodoptera frugiperda (J.E. Smith) on maize and sorghum

The present study was undertaken to assess the biology and life-fecundity tables of Spodoptera frugiperda on maize and sorghum under laboratory condition. Lowest total life cycle duration of male was noticed on maize (27.61 days) and highest on sorghum (31.31 days). Similarly, minimum duration of life cycle of female S. frugiperda was (29.78 days) recorded on maize followed by sorghum (32.52 days). The survival of immature stages (l_x) to the extent of 0.77 and 0.74, per individual within a pivotal age of 22 and 27 days, the net reproductive rate (R_o) was 163.50 and 35.85, females per generation, the mean length of generation time (T) is 27.13, 32.45, days, innate capacity for increase in numbers (r_m) was 0.188 and 0.110 females per female per day and finite rate of increase in numbers (λ) to the extent of 1.20 and 1.12 females per female, on maize on sorghum respectively. The stable age-distribution of the population of S. frugiperda reared maize in egg, larval, pupal and adult stages contributed to the extent of 23.24, 63.61, 9.12 and 4.03 per cent, respectively. In sorghum, stable age-distributions were 23.16, 67.50, 7.50 and 1.84 per cent in egg, larval, pupal and adult, respectively.