Laboratory of Zoology, University of Mons, Mons, Belgium.
Plant Ecology and Nature Conservation Group, Wageningen University, Wageningen, The Netherlands.
J Anim Ecol. 2021 Oct;90(10):2421-2430. doi: 10.1111/1365-2656.13553. Epub 2021 Jun 29.
Bumble bees (Bombus) are a group of eusocial bees with a strongly generalised feeding pattern, collecting pollen from many different botanical families. Though predominantly generalists, some bumble bee species seem to have restricted dietary choices. It is unclear whether restricted diets in bumble bees are inherent or a function of local conditions due to a lack of data for many species across different regions. The objective of this study was to determine whether bumble bee species displayed specific patterns of pollen collection, and whether patterns were influenced by phylogenetic relatedness or tongue length, a trait known to be associated with structuring floral visitation. Bumble bee pollen collection patterns were quantified from 4,132 pollen loads taken from 58 bumble bee species, representing 24% of the pollen-collecting diversity of this genus. Phylogenetic trait mapping showed a conserved pattern of dietary dissimilarity across species, but not for dietary breadth. Dietary dissimilarity was driven by collection of Fabaceae, with the most similar species collecting around 50%-60% of their diet from this botanical family. The proportion of the diet collected from Fabaceae also showed a conserved phylogenetic signal. Greater collection of Fabaceae was associated with longer tongue lengths, with shorter tongued species focusing on alternative botanical families. However, this result was largely driven by phylogenetic relatedness, not tongue length per se. These results demonstrate that, though generalists, bumble bees are still subject to dietary restrictions that constrain their foraging choices. These dietary constraints have implications for their persistence should their core resources decline in abundance.
熊蜂（Bombus）是一组具有强烈普遍化觅食模式的社会性蜜蜂，从许多不同的植物科中收集花粉。尽管它们主要是广食性的，但有些熊蜂物种似乎对食物有特定的选择。由于缺乏许多不同地区的许多物种的数据，因此尚不清楚熊蜂的受限饮食是内在的还是由于当地条件的限制。本研究的目的是确定熊蜂物种是否表现出特定的花粉收集模式，以及这些模式是否受到系统发育关系或舌长的影响，舌长是与花访问结构相关的特征。从 58 种熊蜂采集的 4132 个花粉负荷中定量了熊蜂的花粉采集模式，这代表了该属花粉采集多样性的 24%。系统发育特征映射显示出物种间饮食相似性的保守模式，但饮食广度没有。饮食相似性是由豆科植物的收集驱动的，最相似的物种从该植物科中收集约 50%-60%的食物。从豆科植物收集的饮食比例也显示出保守的系统发育信号。收集更多的豆科植物与更长的舌长有关，而舌短的物种则专注于替代的植物科。然而，这一结果主要是由系统发育关系驱动的，而不是舌长本身。这些结果表明，尽管是广食性的，但熊蜂仍然受到饮食限制的限制，这些限制限制了它们的觅食选择。如果它们的核心资源数量减少，这些饮食限制会对它们的生存产生影响。
