Influence of pollen substitute feeding on colony development of Apis mellifera during resource scarcity

Abstract

Honey bees play a vital role in both the production of high-value hive products and the pollination of a wide range of crops, making them indispensable to global agriculture. However, during dearth periods when natural sources of nectar and pollen are limited, colony strength often declines, threatening brood rearing and overall productivity. Nutritional supplementation through pollen substitute diets has emerged as an important strategy to sustain colonies under such conditions. To evaluate their effectiveness, experiments were conducted during the dearth seasons of 2021 and 2022 at the apiary of the Horticultural Research Farm, Chaudhary Charan Singh Haryana Agricultural University, Hisar. Pooled results from both years revealed that treatment T10 (Bee Pollen + Honey) produced the highest mean colony strength (8.21 frames), demonstrating a significant positive impact on brood development and foraging activity. This superior performance was attributed to the synergistic nutritional benefits of combining natural pollen with honey. The second-best results were obtained with treatment T7 (a formulated diet of dehusked parched gram flour, deactivated yeast, skimmed milk powder, sugar, water, turmeric powder, multivitamins, and pollen), which achieved a mean strength of 7.48 frames. This was followed by T6 (T3 + 10% Bee Pollen) with a mean of 7.20 frames, suggesting that the inclusion of yeast, turmeric, and multivitamins enhanced colony vitality, possibly by boosting immunity and resilience. Overall, the findings highlight that carefully formulated pollen substitute diets can effectively maintain colony strength during forage scarcity, with Bee Pollen + Honey proving to be the most beneficial option.