Using social information can be an efficient strategy for learning in a new environment while reducing the risks associated with trial-and-error learning. Whereas social information from conspecifics has long been assumed to be preferentially attended by animals, heterospecifics can also provide relevant information. Because different species may vary in their informative value, using heterospecific social information indiscriminately can be ineffective and even detrimental. Here, we evaluated how selective use of social information might arise at a proximate level in bumblebees (Bombus terrestris) as a result of experience with demonstrators differing in their visual appearance and in their informative value as reward predictors. Bumblebees were first trained to discriminate rewarding from unrewarding flowers based on which type of “heterospecific” (one of two differently painted model bees) was next to each flower. Subsequently, these bumblebees were exposed to a novel foraging context with two live painted bees. In this novel context, observer bumblebees showed significantly more social information-seeking behavior towards the type of bees that had predicted reward during training. Bumblebees were not attracted by paint-marked small wooden balls (moved via magnets) or paint-marked non-pollinating heterospecifics (woodlice; Porcellio laevis) in the novel context, indicating that bees did not simply respond to conditioned color cues nor to irrelevant social cues, but rather had a “search image” of what previously constituted a valuable, versus invaluable, information provider. The behavior of our bumblebees suggests that their use of social information is governed by learning, is selective, and extends beyond conspecifics.

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10Bees efficiently learn asocial and social cues to optimize foraging from fluctuating 11 floral resources. However, it remains unclear how bees respond to divergent sources of 12 social information, and whether such social cues might modify bees' natural preferences 13 for asocial cues (e.g. flower colour), hence affecting foraging decisions. Here, we 14 investigated honeybees' (Apis mellifera) inspection and choices of unfamiliar flowers 15 based on both natural colour preferences and simultaneous foraging information from 16 conspecifics and heterospecifics. Individual honeybees' preferences for flowers were 17 recorded when the reward levels of a learned flower type have declined and novel-18 coloured flowers were available where they would find either no social information or 19 one conspecific and one heterospecific (Bombus terrestris), each foraging from a 20 different coloured flower (either magenta or yellow). Honeybees were found to have a 21 natural preference for magenta flowers. Social information affected honeybees' 22 inspection time of both types of flowers, i.e., honeybees modified their approaching 23 flights to yellow and magenta flowers in response to conspecific and heterospecific 24 social information. The presence of either demonstrator on the less-preferred yellow 25 flower increased honeybees' inspection time of yellow flowers. Conspecific social 26 information influenced observers' foraging choices of yellow flowers, thus outweighing 27 their original preference for magenta flowers, such an influence was not elicited by 28 heterospecific social information. Our results indicate that flower colour preferences of 29 honeybees are rapidly adjusted in response to conspecific social information, which in 30 turn is preferred over heterospecific information, thus favouring the transmission of 31 adaptive foraging information within species. 32 33