Data from: Bees without flowers: before peak bloom, diverse native bees find insect-produced honeydew sugars

Bee foragers respond to complex visual, olfactory, and extrasensory cues to optimize searches for floral rewards. Their abilities to detect and distinguish floral colors, shapes, volatiles, and ultraviolet signals, and even gauge nectar availability from changes in floral humidity or electric fields are well studied. Bee foraging behaviors in the absence of floral cues, however, are rarely considered. We observed forty-two species of wild bees visiting inconspicuous, non-flowering shrubs during early spring in a protected Mediterranean habitat. We determined experimentally that these bees were accessing sugary honeydew secretions from scale insects without the aid of standard cues. While honeydew use is known among some social Hymenoptera, its use across a diverse community of solitary bees is a novel observation. The widespread ability of native bees to locate and use unadvertised, non-floral sugars suggests unappreciated sensory mechanisms and/or the existence of an interspecific foraging network among solitary bees that may influence how native bees cope with scarcity of floral resources and increasing environmental change.

觅食蜂会借助复杂的视觉、嗅觉及超感官线索优化花源奖励的搜寻过程。学界已对其检测、区分花卉颜色、形状、植物挥发物与紫外信号的能力，乃至通过花卉湿度或电场变化评估花蜜供应量的能力开展了充分研究。然而，无花卉线索场景下的蜜蜂觅食行为却极少受到关注。我们在一处受保护的地中海生境中，于早春时节观察到42种野生蜂造访不起眼的非开花灌木。经实验证实，这些蜜蜂无需依赖常规觅食线索，即可取食介壳虫分泌的含糖蜜露。尽管部分社会性膜翅目昆虫已知会取食蜜露，但在多样的独居蜂类群落中发现此类取食行为尚属首次。本土野生蜂广泛具备定位并利用未被常规花卉信号提示的非花源糖分的能力，这暗示存在尚未被认知的感官机制，或是独居蜂之间存在种间觅食网络——这类机制或网络或可影响本土蜂类应对花卉资源匮乏与日益严峻的环境变化的方式。