comprative life table parameters of the spodoptera exigua (hübner) (lepidoptera: noctuidae) on corn hybrids under laboratory conditions

the effects of four corn hybrids, keynes540, keynes410, ksc260 and ksc400, were investigated on life table parameters of the beet armyworm in a growth chamber that was set at 25 ± 1 ºc, 65 ± 5% rh and 16:8 (l: d) photoperiod. the highest survivorship (lx) of adults were 0.77, 0.70, 0.62 and 0.58 on ksc260, keynes410, keynes540 and ksc400, respectively. the highest age-specific fecundity (mx) of females which were emerged from the larvae being fed on above-mentioned hybrids were recorded 28.75, 21.70, 20.37 and 16.33 female/ female/ day, that occurred at the days 39, 40, 41 and 45, respectively. the females reared on ksc400 showed the lowest net reproductive rate (r0), while the highest r0 was recorded on ksc260 hybrids. the intrinsic rate of natural increase (rm) ranged from 0.1028 to 0.1370 day-1 of which the lowest was on ksc400. the lowest and highest values of finite rate of increase (λ)were obtained on ksc400 and keynes540, respectively. the longest mean generation time (t)(35.37 ± 0.83 days) was observed on ksc400 and the shortest one (30.67 ± 0.93 days) was on keynes410. the results showed that ksc400 was the least suitable host for s. exigua.