RESEARCH ARTICLE Visual and Olfactory Floral Cues of Campanula (Campanulaceae) and Their Significance for Host Recognition by an Oligolectic Bee Pollinator Paulo Milet-Pinheiro1*, Manfred Ayasse1, Stefan Dötterl2¤ 1 Institute of Experimental Ecology, University of Ulm, Ulm, Germany, 2 Department of Plant Systematics, University of Bayreuth, Bayreuth, Germany ¤ Current address: Department of Organismic Biology, University of Salzburg, Salzburg, Austria a11111 *
[email protected] Abstract Oligolectic bees collect pollen from a few plants within a genus or family to rear their off- spring, and are known to rely on visual and olfactory floral cues to recognize host plants. OPEN ACCESS However, studies investigating whether oligolectic bees recognize distinct host plants by Citation: Milet-Pinheiro P, Ayasse M, Dötterl S using shared floral cues are scarce. In the present study, we investigated in a comparative (2015) Visual and Olfactory Floral Cues of Campanula (Campanulaceae) and Their Significance approach the visual and olfactory floral cues of six Campanula species, of which only Cam- for Host Recognition by an Oligolectic Bee Pollinator. panula lactiflora has never been reported as a pollen source of the oligolectic bee Ch. PLoS ONE 10(6): e0128577. doi:10.1371/journal. rapunculi. We hypothesized that the flowers of Campanula species visited by Ch. rapunculi pone.0128577 share visual (i.e. color) and/or olfactory cues (scents) that give them a host-specific signa- Academic Editor: Adrian G Dyer, Monash ture. To test this hypothesis, floral color and scent were studied by spectrophotometric and University, AUSTRALIA chemical analyses, respectively. Additionally, we performed bioassays within a flight cage Received: February 5, 2015 to test the innate color preference of Ch.