caa a22 4500 606193367 CHVBK 20210128100909.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s10682-014-9716-9 doi (NATIONALLICENCE)springer-10.1007/s10682-014-9716-9 Bee- to bird-pollination shifts in Penstemon [Elektronische Daten] effects of floral-lip removal and corolla constriction on the preferences of free-foraging bumble bees [Jessica Zung, Jessica Forrest, Maria Castellanos, James Thomson] Plants might be under selection for both attracting efficient pollinators and deterring wasteful visitors. Particular floral traits can act as exploitation barriers by discouraging the unwelcome visitors. In the genus Penstemon, evolutionary shifts from insect pollination to more efficient hummingbird pollination have occurred repeatedly, resulting in the convergent evolution of floral traits commonly present in hummingbird-pollinated flowers. Two of these traits, a reduced or reflexed lower petal lip and a narrow corolla, were found in a previous flight-cage study to affect floral handling time by bumble bees, therefore potentially acting as "anti-bee” traits affecting preference. To test whether these traits do reduce bumble bee visitation in natural populations, we manipulated these two traits in flowers of bee-pollinated Penstemon strictus to resemble hummingbird-adapted close relatives and measured the preferences of free-foraging bees. Constricted corollas strongly deterred bee visitation in general, and particularly reduced visits by small bumble bees, resulting in immediate specialization to larger, longer-tongued bumble bees. Bees were also deterred—albeit less strongly—by lipless flowers. However, we found no evidence that lip removal and corolla constriction interact to further affect bee preference. We conclude that narrow corolla tubes and reduced lips in hummingbird-pollinated penstemons function as exploitation barriers that reduce bee access to nectaries or increase handling time. Springer International Publishing Switzerland, 2014 Bombus nationallicence Floral morphology nationallicence Pollination syndromes nationallicence Pollinator visitation nationallicence Preference nationallicence Zung Jessica Department of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord St., M5S 3G5, Toronto, ON, Canada aut Forrest Jessica Rocky Mountain Biological Laboratory, 81224, Crested Butte, CO, USA aut Castellanos Maria Consejo Superior de Investigaciones Científicas, Centro de Investigaciones sobre Desertificación (CSIC-UV-GV), 46113, Moncada, Valencia, Spain aut Thomson James Department of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord St., M5S 3G5, Toronto, ON, Canada aut Evolutionary Ecology Springer International Publishing 29/3(2015-05-01), 341-354 0269-7653 29:3<341 2015 29 10682 https://doi.org/10.1007/s10682-014-9716-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10682-014-9716-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zung Jessica Department of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord St., M5S 3G5, Toronto, ON, Canada aut NATIONALLICENCE 700 1- Forrest Jessica Rocky Mountain Biological Laboratory, 81224, Crested Butte, CO, USA aut NATIONALLICENCE 700 1- Castellanos Maria Consejo Superior de Investigaciones Científicas, Centro de Investigaciones sobre Desertificación (CSIC-UV-GV), 46113, Moncada, Valencia, Spain aut NATIONALLICENCE 700 1- Thomson James Department of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord St., M5S 3G5, Toronto, ON, Canada aut NATIONALLICENCE 773 0- Evolutionary Ecology Springer International Publishing 29/3(2015-05-01), 341-354 0269-7653 29:3<341 2015 29 10682