Floral quality signals lure pollinators and their predators

Flowers exploit the sensory capabilities of pollinators to lure them. The crab spider Thomisus spectabilis benefits from this system by responding to floral signals that are intended to lure honeybees, Apis mellifera, which they prey upon. We investigated whether honeybees and crab spiders discriminate between flowers of Jasminum mesnyi plants that are either fully rewarding, with two reproductive stamens, or not. We found that both honeybees and crab spiders preferred fully rewarding flowers in the field. Moreover, honeybees preferred small flowers over larger ones, while the height above the ground and the number of petals did not influence flower choice of honeybees and crab spiders. Under experimental conditions, crab spiders showed the same choice pattern as observed in the field. This indicates that they actively search for fully rewarding flowers, which are also preferred by their potential prey. Fully rewarding J. mesnyi lure honeybees through visual, olfactory or a combination of these floral signals and T. spectabilis exploits this communication to enhance their chance of prey encounter.