Comparative evaluation of commercial protein supplements on honey bee (Apis mellifera) health under laboratory conditions

Honey bees are crucial pollinators of agricultural crops, and during periods of floral scarcity, beekeepers often rely on protein supplements to maintain colony strength. These protein supplements are intended to provide sufficient protein, essential amino acids, and minerals to support bee health and brood development. However, their nutritional value compared to natural pollen remains uncertain. In this study, we investigated the effects of three commercial protein supplements (P1, P2, and P3) on honey bee consumption, survival, and physiological traits under laboratory conditions over two years. We also assessed their digestibility. Mixed pollen and a no-protein group were included as positive and negative controls, respectively. Results showed that bees fed mixed pollen had the highest survival rates, body weight, and head protein content, indicating its superior nutritional quality. Among the protein supplements, P3 was consumed most, followed by P1 and P2. However, despite its higher intake and digestibility, bees fed P3 showed significantly lower survival than those fed P1 and P2. No significant differences were observed among supplements in body weight or head protein content. These findings suggest that while commercial protein supplements can partially support honey bee physiology, they may not provide the full benefits of natural pollen. The mismatch between supplement consumption and survival highlights the importance of evaluating not just palatability, but also nutritional efficacy. Since laboratory conditions do not fully mimic field environments, further research is needed under natural foraging conditions to assess the long-term impact of these supplements on colony performance, brood development, and overall productivity.