Enrichment of diverse seed-based artificial diets with date palm pollen affects the fitness and physiological responses of Spodoptera littoralis (Boisduval, 1833)

Artificial diets incorporating plant-derived components can improve nutrition and reduce costs in insect rearing. This study evaluated five seed-based diets enriched with date palm pollen for Spodoptera littoralis (Boisduval, 1833) by examining ecological parameters, food utilization, enzymatic activities, and plant biochemical composition. Diets (D1–D5) combined date palm pollen with cowpea (D1), chickpea (D2), beet (D3), mung bean (D4), or maize (D5) seed powders. Diets D1 and D4 significantly enhanced key fitness traits, including oviposition period, adult longevity, net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ). Diets D4 and D5 improved food utilization efficiency and larval growth rate (RGR). Enzymatic analyses showed elevated amylolytic and proteolytic activities with D4 and D5, while D3 triggered the highest antioxidant enzyme activity, likely aiding detoxification of beet seed phenolics. Overall, D1 and D4 were the most effective diets for S. littoralis rearing, demonstrating promise for mass production applications.