Influence of Pollen Trapping on Growth of Apis mellifera Linneaus, 1758 Colony Under Mustard Flowering Season

Bee pollen has diverse applications beyond human consumption and bee supplement. Its economic advantages may encourage beekeepers to adopt frequent pollen trapping, yet its impacts on brood rearing remains poorly understood. This study aimed to standardize pollen trapping using front-mounted traps with 50% efficiency on Apis mellifera L. colonies. The effects of different trapping frequencies on pollen load collection, pollen foraging, and brood production were evaluated in 12-frame colonies across two apiaries in Hisar and Kaul, Haryana, India during the mustard flowering seasons of 2017 and 2018. Five experimental groups each with three colonies were established in both apiaries and mounted with traps based on pollen trapping frequencies viz. daily, alternate day, third day, weekly and control (no trapping) with respective duration of 42, 21, 14, 7 and 0 days. Daily trapping yielded maximum pollen load collection (0.56 Kg/colony at Hisar and 1.89 Kg/ colony at Kaul) but reduced brood area by 27.3% at Hisar and retarded brood expansion at Kaul. Conversely, weekly-trapped and control colonies, exhibited larger brood area, indicating a strong negative correlation between trapping frequency and brood area. Mustard season at Kaul exhibited greater pollen diversity (0.70-1.42) and higher protein content (24.3-30.2%). In both locations, pollen foraging peaked between 10:00 AM and 2:00 PM. Therefore, adopting intermittent pollen trapping or restricting daily trapping to peak foraging hours (10:00 AM- 2:00 PM) could be viable strategies to balance pollen collection with colony health.