Comparative demographic parameters of beet armyworm, Spodoptera exigua (Lep.: Noctuidae) on four commercial sugar beet cultivars

The effects of four sugar beet cultivars (Anaconda, Rozier, Evelina and Flores) on the life table parameters of beet armyworm, Spodoptera exigua (Lep.: Noctuidae) were evaluated at 26 ± 1 °C, 60 ± 5% relative humidity and a photoperiod of 16: 8 h (L: D). The highest gross and net fecundity rates were obtained on Anaconda (2573.31 ± 27.78 and 1576.31 ± 16.65 eggs/female, respectively). The net reproductive rate (R0) was the highest on Anaconda (341.38 ± 56.31 female offspring) and the lowest on Flores and Evelina (106.30 ± 22.4 and 144.62 ± 30.81 female offspring), respectively. The intrinsic rate of increase (r) was affected by different sugar beet cultivars, ranging from 0.197 day (on Flores) to 0.274 day (on Anaconda). The highest value of finite rate of increase (λ) was on Anaconda (1.31 day). The mean generation time (Tc) was different on the various cultivars, ranging from 21.04 ± 0.60 days (on Anaconda) to 23.68 ± 0.38 days (on Flores). Results of the demographic parameters revealed that Anaconda was the most suitable host plant among the mentioned sugar-beet cultivars for S. exigua.