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Taste plays a crucial role in the life of honey bees as their survival depends on the collection and intake of nectar and pollen, and other natural products. Here we studied the tarsal taste of honey bees through a series of behavioral and electrophysiological analyses. We characterized responsiveness to various sweet, salty and bitter tastants delivered to gustatory sensilla of the fore tarsi. Behavioral experiments showed that stimulation of opposite fore tarsi with sucrose and bitter substances or water yielded different outcomes depending on the stimulation sequence. When sucrose was applied first, thereby eliciting proboscis extension, no bitter substance could induce proboscis retraction, thus suggesting that the primacy of sucrose stimulation induced a central excitatory state. When bitter substances or water were applied first, sucrose stimulation could still elicit proboscis extension but to a lower level, thus suggesting central inhibition based on contradictory gustatory input on opposite tarsi. Electrophysiological experiments showed that receptor cells in the gustatory sensilla of the tarsomeres are highly sensitive to saline solutions at low concentrations. No evidence for receptors responding specifically to sucrose or to bitter substances was found in these sensilla. Receptor cells in the gustatory sensilla of the claws are highly sensitive to sucrose. Although bees do not possess dedicated bitter-taste receptors in the tarsi, indirect bitter detection is possible because bitter tastes inhibit sucrose receptor cells of the claws when mixed with sucrose solution. By combining behavioral and electrophysiological approaches, these results provide the first integrative study on tarsal taste detection in the honey bee.

The purpose of this study is to evaluate the role of small urban spaces (or pocket parks) in cities as an opportunity to access nature and restorativeness. The study was performed in nine squares located in the central zone of the city of Madrid. A total of 537 people were interviewed in situ about their preferences, as well as the perceived quality and environmental restorativeness of these places. The results show that preference is influenced by the amount of vegetation and perceived restorativeness, and that restorativeness in turn is determined by perceived vegetation and social interaction. The benefits of this restorative role should be considered when designing small urban squares, taking care to include plants and vegetation as well as appropriate equipment, and making these spaces a valuable element within the green infrastructure of major cities.

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