Nectar sources of Asian honeybees ( Apis cerana Fabricius) in West Bengal: determining by pollen analysis of honey and bee’s crop-nectar

Understanding nectar sources is crucial for sustainable apiculture with Apis cerana, yet information on these sources remains limited. We conducted pollen analysis of honey and bees' ingested nectar (mainly crop content) to determine the nectar sources of this honeybee species in West Bengal, India. Diverse pollen types were obtained from honey (33) and crop-nectar samples (47). A few pollen types came from non-nectariferous plants, and most came from actual nectariferous plants. Predominant pollen types in honey samples were Calendula officinalis, Eucalyptus tereticornis, and Peltophorum pterocarpum. The very frequent pollen types obtained from crop-nectar were Eucalyptus tereticornis, Peltophorum pterocarpum, and Tridax procumbens. In conclusion, versatile pollen types (that were obtained from honey and bee's crop-nectar), indicating that the Asian honeybee (Apis cerana) is a generalist visitor, collect nectar from a large number of plant species. Our results also conclude that pollen analysis of bees' crop-nectar can provide vital information about their nectar sources (excluding a few pollen types of non-nectariferous plants) in addition to the traditional honey analysis.