The suitability of artificial diets containing diverse pollen grains to Helicoverpa armigera (Hübner): Population growth performance and antioxidant enzymes activities

In recent years, improving host quality for parasitoids has gained attention due to its importance in providing adequate nutrition for immature stages and ensuring successful adult reproduction. Incorporation of plant materials into artificial diets can significantly influence the performance of host insects. This study evaluated the effects of supplementing a basic artificial diet (control) with various pollen grains (glossy shower, hollyhock, honey bee, maize, date palm, rapeseed, saffron, and sunflower) on population growth performance and antioxidant enzymes activities of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), a commonly used host for parasitoid rearing. All pollen–contained diets supported complete development of H. armigera, though its performance varied among treatments. The shortest developmental time was recorded in larvae fed on the date palm–pollen–contained artificial diet. The female fecundity was highest on date palm–pollen–contained diet (1140.53 offspring), compared to the control diet (331.41 offspring). The intrinsic rate of increase (r) ranged from 0.109 to 0.162 day⁻¹, being highest on honey bee- and date palm–pollen–contained diets and lowest on glossy shower-pollen-contained diet. Meanwhile, the shortest mean generation time (T) was obtained on date palm–pollen–contained diet. The antioxidant enzymes activities, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were elevated in larvae fed on maize–, glossy shower–, and saffron–pollen–contained diets, respectively. The cluster analysis confirmed that the date palm–pollen–incorporated artificial diet most effectively enhanced the quality of H. armigera and thus, can be recommended for use in rearing of this species.