Influence of Maize Pollen and Honey Supplementation on the Reproductive Parameters of Eiphosoma vitticolleCresson, a Parasitoid of the Fall Armyworm

The success of augmentative biological control programmes critically depends on the reproductive capacity of natural enemies, which is strongly modulated by the availability and quality of adult nutritional resources. This study evaluated the effect of four dietary regimes on the reproductive performance of Eiphosoma vitticolle Cresson (Hymenoptera: Ichneumonidae), a larval endoparasitoid of the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae): total fasting (TF), water only (W), water + 10% honey (WH), and water + honey + maize pollen (WHP). A completely randomised design with 15 replicates per treatment was used, and experiments were conducted at 24.5 ± 1.0°C, 76.0 ± 10.0% RH, and a 12:12 h L:D photoperiod. Female longevity was calculated from the preoviposition period, oviposition period, and a uniform post-oviposition survival of two days observed across all treatments. The WHP diet significantly optimised all evaluated parameters, reducing the preoviposition period to 1.60 ± 0.55 days, extending the oviposition period to 17.20 ± 3.96 days, and increasing oviposition rate to 0.83 ± 0.19 eggs host⁻¹ day⁻¹, yielding a total fecundity of approximately 214 eggs per female and a mean female longevity of 20.80 ± 4.00 days. In contrast, females under total fasting survived only 12.02 ± 3.08 days. A significant positive interaction between carbohydrate (honey) and protein (pollen) sources was detected (p < 0.0001), confirming their synergistic effect on fecundity. Maize pollen constitutes an ecologically relevant and economically accessible protein source in Zea mays L. agroecosystems, reflecting the deep coevolutionary history between the host plant, the herbivore, and its parasitoid complex. These findings provide actionable evidence for the design of optimised diets in mass-rearing programmes aimed at enhancing the efficacy of augmentative biological control of S. frugiperda .