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Social but not solitary bees reject dangerous flowers where a conspecific has recently been attacked. Llandres , A.L., Gonzalvez , F.G., & Rodriguez- Girones , M.A. Social vs. Solitary Bees. Social. Solitary. Related bees live together Infertile females Division of labor
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Social but not solitary bees reject dangerous flowers where a conspecific has recently been attacked Llandres, A.L., Gonzalvez, F.G., & Rodriguez-Girones, M.A.
Social vs. Solitary Bees Social Solitary • Related bees live together • Infertile females • Division of labor • A. mellifera, A. dorsata, A. florea, B. terrestris • Bees are isolated • All females fertile • Builds own nest • N. strigata
Introduction • Animals rely on cues to avoid predators • Avoiding flowers with crushed “conspecifics” • Two types of cues produced by prey • By-products of predation • Alarm signals 2-heptanone 2-methylbutyl
Alarm Signals • 2 hypothesized functions: • Signals nectar depletion (Balderrama, 1996) • Increases efficiency • Marks dangerous flowers • Both social and solitary bees respond to volatile cues • Social bees are less wary
Questions • Do bees mark visited flowers to increase efficiency? • Do solitary bees use alarm signals? • No studies for the presence of alarm signals in solitary bees.
Methods • Inflorescence: a cluster of flowers on one stem • Assigned randomly • Experimental • Control • Experimental: bees grasped over the thorax • Control: bees visit flower and leave
Methods • Record number of bees after that rejecting or visiting the flower • Rejection: Bee hovers, then leaves. • Accept: Bee hovers and lands. • All conducted during sunny weather • Tested social bees and solitary bees
Methods • Experiments in six geographical locations • Baza, Spain • Almeria, Spain • Vulluercas-Ibores, Spain • Cannonvale, Australia • MacRitchie Reservoir Park, Singapore • Xishuangbanna, China • Trials conducted as far away as possible • Experimental: 233, Control: 236
Probability of landing vs. Bee species ***: Social Bees (P<.0001) NS: Solitary Bees (P>0.25)
Discussion • Social bees release alarm signals to warn of predators • Treatment had a strong effect on social bees relative to solitary bees • Solitary bees do not release alarm signals • Limitations: All tests were not run at the same place, at the same time. • Different plant species