Influence of stimulating nutritional additives on Apis mellifera L. Colony performance metrics

Nutritional stress related to pollen scarcity is the major cause of honeybee colony collapse during winter in Egypt. It also affects the colonies' ability to build up in early spring. In this study, the effect of four stimulating nutritional additives: (Spirulina, Chlorella, Moringa, pollens, along a treatment comprising of their mixture) on wintering ability, colony development, foraging activity, and citrus honey yield was evaluated from November 2024 to April 2025 at the Faculty of Agriculture, Benha University, Egypt. Colonies treated with the algae (Spirulina, Chlorella and mixture) showed better wintering ability. Similarly, all developmental indicators (egg area, sealed worker brood area, stored pollen, and number of bees) of the algae-supplemented colonies increased compared with those of the control colonies, with the greatest improvement observed in the chlorella-fed colonies. Foraging activity also increased in the algae-fed colonies, reflecting their growth metrics. Ultimately, the citrus honey yield was highest in the algae-fed colonies, with the spirulina-fed colonies producing the most. Our results provide novel insights into the mechanism by which nutritional additives can be used to reduce nutritional stress associated with a lack of natural pollen supply, particularly when using algae (Spirulina, Chlorella), thereby improving colony performance and increasing honey production.