Abstract
<jats:p>Nutritional supplementation with pollen and protein-based patties is widely used in apiculture to support honey bees (Apis mellifera carnica, Pollmann 1879) colonies during periods of limited natural forage, particularly in early spring and late summer. This study evaluated the effects of different supplemental diets on the survival, food intake, and gross energy content of caged adult worker bees of mixed ages under controlled laboratory conditions. Worker bees were fed four different diets: sucrose syrup (control), sugar patty, protein patty, and pollen patty. Survival, food intake, and gross energy content were assessed over an 18-day experimental period. Calorimetric analyses demonstrated that diet composition significantly influenced the gross energy content of adult bee tissues. Bees fed pollen patty exhibited the highest energy values (22.05 ± 0.38 MJ/kg), particularly among young (22.28 ± 0.18 MJ/kg) and middle-aged workers (22.26 ± 0.23 MJ/kg), indicating enhanced energy accumulation during early adult development. In contrast, although sucrose syrup had the highest intrinsic caloric value among the tested diets (16.56 ± 0.01 MJ/kg), it resulted in the lowest gross energy accumulation in bee tissues (20.92 ± 0.40 MJ/kg), suggesting that nutrient composition, rather than caloric density alone, determines physiological outcomes. These findings highlight the importance of nutritionally complex pollen‑ and protein‑based supplements for supporting worker bee physiological conditions during periods of food scarcity and provide new insights into the relationship between dietary energy content and energy reserves accumulated in bee tissues.</jats:p>