TY - JOUR T1 - Floral scent and pollinators of Ceropegia trap flowers JF - Flora Y1 - 2017 DO - http://dx.doi.org/10.1016/j.flora.2017.02.001 A1 - A Heiduk A1 - Irina Brake A1 - Tschirnhaus, M. von A1 - Haenni, J. P. A1 - Miller, R. A1 - Hash, J. A1 - Prieto-Benítez, S. A1 - Jürgens, A. A1 - Johnson, S. D. A1 - Schulz, S. A1 - Liede-Schumann, S. A1 - Meve, U. A1 - Dötterl, S. SP - 169–182 KW - Chemical mimicry KW - Deceptive strategy KW - Fly pollination KW - Pollen transfer efficiency KW - Scent specificity AB -

Ceropegia L. (Apocynaceae, Asclepiadoideae) comprises more than 200 species, all characterized by complex pitfall flowers. The deceptive flowers are myiophilous and pollinated predominantly by small flies from different families. It has been suggested that floral scent cues, that mimic food sources or oviposition sites, play an important role for attraction of target fly pollinators, and, together with morphological flower traits, explain the high functional specialization in terms of pollination by specific taxa. However, apart from two Ceropegia species, the floral scent composition and the mimicry strategies in this genus are unexplored. We tested for associations between floral scent and insect visitor and pollinator assemblages of 14 Ceropegia species. We also used nrDNA and chloroplast DNA markers to calculate a Maximum Likelihood tree and test for phylogenetic signal in scent chemistry and flower visitors/pollinators. The observed pollinators belonged to eight fly families, at least 18 genera, and 33 morphospecies, but each Ceropegia species was typically associated with only one or two pollinating fly families or genera. We detected a total of 317 floral volatiles, including aliphatic and aromatic components, terpenes, and various unknowns. Both flower visitor and pollinator patterns did not show an overall association with floral
scent chemistry. There was phylogenetic signal in flower visiting fly families and fly pollinator assemblages, but not in flower visiting fly morphospecies and overall scent chemistry. We discuss that despite the not existing correlation between pollinator and scent patterns the highly specific pollination system in Ceropegia will be explained mainly by floral scent chemistry.

VL - 232 ER - TY - JOUR T1 - Ceropegia sandersonii mimics attacked honeybees to attract kleptoparasitic flies for pollination JF - Current Biology Y1 - 2016 A1 - A Heiduk A1 - Irina Brake A1 - Tschirnhaus, M. von A1 - Göhl, M. A1 - Jürgens, A. A1 - Johnson, S. D. A1 - Meve, U. A1 - Dötterl, S. SP - 1 EP - 7 AB -

Four to six percent of plants, distributed over different angiosperm families, entice pollinators by deception [1]. In these systems, chemical mimicry is often used as an efficient way to exploit the olfactory preferences of animals for the purpose of attracting them as pollinators [2,3]. Here, we report a very specific type of chemical mimicry of a food source. Ceropegia sandersonii (Apocynaceae), a deceptive South African plant with pitfall flowers, mimics attacked honeybees. We identified kleptoparasitic Desmometopa flies (Milichiidae) as the main pollinators of C. sandersonii. These flies are well known to feed on honeybees that are eaten by spiders, which we thus predicted as the model chemically mimicked by the plant. Indeed, we found that the floral scent of C. sandersonii is comparable to volatiles released from honeybees when under simulated attack. Moreover, many of these shared compounds elicited physiological responses in antennae of pollinating Desmometopa flies. A mixture of four compounds—geraniol, 2-heptanone, 2-nonanol, and (E)-2-octen-1-yl acetate—was highly attractive to the flies. We conclude that C. sandersonii is specialized on kleptoparasitic fly pollinators by deploying volatiles linked to the flies’ food source, i.e., attacked and/or freshly killed honeybees. The blend of compounds emitted by C. sandersonii is unusual among flowering plants and lures kleptoparasitic flies into the trap flowers. This study describes a new example of how a plant can achieve pollination through chemical mimicry of the food sources of adult carnivorous animals.

VL - 26 UR - http://dx.doi.org/10.1016/j.cub.2016.07.085 ER - TY - JOUR T1 - Scent chemistry and pollinator attraction in the deceptive trap flowers of Ceropegia dolichophylla JF - South African Journal of Botany Y1 - 2010 A1 - A Heiduk A1 - Irina Brake A1 - Tolasch, T. A1 - Frank, J. A1 - Jürgens, A. A1 - Meve, U. A1 - Dötterl, S. SP - 762 KW - China KW - Desmometopa sordida KW - Germany KW - Milichiidae KW - Neophyllomyza acyglossa KW - Neophyllomyza sp. KW - pollination AB - Ceropegia species (Apocynaceae, Asclepiadoideae) have pitfall flowers and are pollinated by small flies through deception. It has beensuggested that these flies are attracted by floral scent. However, the scent that is emitted from Ceropegia flowers has not been studied usingheadspace and gas chromatography mass spectrometry methods. It has also been unclear whether or not the flowers are mimics of particularmodels that attract flies. In the present study, we determined the composition as well as the spatial and temporal patterns of floral scent emitted byC. dolichophylla. Furthermore, we determined the pollinators in the native (China) and non-native (Germany) range of this species, and tested thecapability of the floral scent to attract flies in the non-native range. Our data demonstrate that the floral scent, which is emitted from morning untilevening, primarily from the tips of the corolla lobes, consists mainly of spiroacetals and aliphatic compounds. Milichiid flies were commonvisitors/pollinators in the native as well as non-native range, and were attracted by floral scent in bioassays performed in the non-native range. Thecompounds emitted by C. dolichophylla are unusual for flowers, but are well known from insect pheromones and occur in the glandular secretionsof insects. The milichiid flies that visit and pollinate the flowers are kleptoparasites that feed on the prey (haemolymph or other secretions) ofpredatory arthropods, e.g. spiders, to which they are attracted by scent. Our data thus suggest that the floral scent of C. dolichophylla mimics thefeeding sites of kleptoparasitic flies. VL - 76 UR - http://milichiidae.info/sites/milichiidae.info/files/Heiduk%20et%20al_2010.pdf U1 - pdf ER -