Nectar sources of Asian honeybees (<i>Apis cerana</i> Fabricius) in West Bengal, India: determined by pollen analysis of honey and bee crop nectar

Understanding nectar sources is crucial for sustainable apiculture with <i>Apis cerana</i>, 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 <i>Calendula officinalis</i>, <i>Eucalyptus tereticornis</i>, and <i>Peltophorum pterocarpum</i>. The very frequent pollen types obtained from crop nectar were <i>Eucalyptus tereticornis</i>, <i>Peltophorum pterocarpum</i>, and <i>Tridax procumbens</i>. In conclusion, versatile pollen types (that were obtained from honey and bees’ crop nectar) indicate that the Asian honeybee (<i>Apis cerana</i>) is a generalist visitor, collecting nectar from a large number of plant species. Our results also show 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.

探明蜜源植物对于东方蜜蜂（Apis cerana）的可持续养蜂至关重要，但目前相关蜜源信息仍较为匮乏。本研究针对印度西孟加拉邦地区的该蜂种，通过对蜂蜜及蜜蜂采食的花蜜（主要为蜜囊内容物）开展花粉分析，以明确其蜜源来源。从蜂蜜样本（33份）与蜜囊花蜜样本（47份）中均获取到丰富的花粉类型，其中少量源自无蜜腺植物，绝大多数则来自真正产蜜的蜜腺植物。蜂蜜样本中的优势花粉类型为金盏花（Calendula officinalis）、细叶桉（Eucalyptus tereticornis）与盾柱木（Peltophorum pterocarpum）；从蜜囊花蜜样本中获取的高频花粉类型则为细叶桉（Eucalyptus tereticornis）、盾柱木（Peltophorum pterocarpum）以及羽芒菊（Tridax procumbens）。综上，从蜂蜜与蜜蜂蜜囊花蜜中获取的多样花粉类型表明，东方蜜蜂（Apis cerana）为泛化访花者，可从大量不同植物类群中采集花蜜。本研究结果同时证实，相较于传统的蜂蜜花粉分析方法，对蜜蜂蜜囊花蜜开展花粉分析，还可获取其蜜源相关的关键信息（仅排除少量无蜜腺植物的花粉类型）。