Forecasting life table parameters of Cabbage Aphid Brevicone brassica (L.)Hemiptera: Aphididae using differential Nitrogen-regimes in kale

The interactions between plants and herbivores are influenced by the increased application of nitrogen to crops, which has the potential to enhance the growth of herbivore populations. This study evaluates the impact of nitrogen fertilization on the life table parameters of cabbage aphid using kale ( Brassica oleracea var. acephala ) as a host plant under controlled greenhouse conditions. Nine nitrogen treatments (ranging from 0% to 200% of the recommended dose) were applied, while other biotic and abiotic factors were kept constant. Aphid performance was assessed based on developmental and reproductive metrics, including pre-reproductive period, reproductive and post-reproductive periods, adult longevity, mean daily fecundity, net reproductive rate (R₀), intrinsic rate of increase (rₘ), finite rate of increase (λ), mean generation time (T), and population doubling time. Linear regression models revealed strong, statistically significant relationships between nitrogen levels and cabbage aphid’s life history traits. Increased nitrogen availability extended reproductive and post-reproductive periods, enhanced mean daily fecundity, and reduced the pre reproductive period, mean generation and doubling times, leading to faster population growth. While as the intrinsic rate of increase and net reproductive rate both showed robust positive correlations with nitrogen levels (R² >0.9, p < 0.001). These results highlight the critical influence of nitrogen in shaping pest population dynamics and stress the importance of balanced fertilization strategies. Excessive nitrogen application, while promoting plant growth, can inadvertently intensify aphid infestations. The study advocates for integrated pest and nutrient management approaches to sustainably mitigate the pest pressures on kale plant .