The study of multi-modal communication has only recently been extended to innate and learned interactions between flowers and their animal visitors, and usually only to pollinators. Here we studied the relevance of fl...The study of multi-modal communication has only recently been extended to innate and learned interactions between flowers and their animal visitors, and usually only to pollinators. Here we studied the relevance of floral scent and visual display of a night blooming, putatively hawkmoth-pollinated plant Oenothera acaulis （Onagraceae） in the attraction of non-native cockroaches Blatta orientalis （Blattodea： Blattidae）, which function as facultative floral larcenists in coastal habitats of central Chile. We experimentally decoupled visual （corolla） and olfactory （fragrance） stimuli by presenting paper corollas and green mesh bags, with or without a freshly-picked natural flower inside. We then contrasted the behavioral responses of roaches in these treatments with those to the natural combination of traits in actual flowers and their respective control treatments, measuring the roaches＇ frequency of first visits, mean and total residence time spent in each treatment. The roaches primarily used olfactory cues when approaching O. acaulis flowers at two biologically relevant spatial scales. In addition, the presence of conspecific roaches had a strong influence on recruitment to the experimental arena, increasing the statistical differences among treatments. Our results suggest a primacy of floral fragrance over visual stimuli in the foraging responses of B. orientalis. Olfactory cues were necessary and sufficient to attract the roaches, and the visual cues presented in our manipulations only marginally increased their attraction within a 20 cm diameter of the stimulus. The full spectrum of floral visitation behavior was not elicited by the artificial flowers, suggesting the need for additional tactile or contact chemosensory stimuli not provided by paper. Although the nitrogenous scent compounds that we found in O. acaulis flowers are almost exclusively found in hawkmoth-pollinated flowers, the attractiveness of these compounds to a non-native, facultative flower-visiting insect indicates that they do not function as pollinator-specific signals for hawkmoth attraction .展开更多
基金Acknowledgements We thank F. Salinas and A. Villagra for their help finding Oenothera acaulis populations in coastal Central Chile, and S. Herrera and R. Yuri for their help with the field experiments. We acknowledge J. C. Ortuzar, J. Alcayaga, M. Cannals and D. Dominguez, A. Jimenez and R. Suarez for their statistical advices and constructive comments. Special thanks to R. Kaiser for the generous gift of authentic standard compounds for 3-methyl butyraldoxime and 2-methyl butyraldoxime for GC-MS analysis of floral scent. This research was funded by postdoctoral FONDECYT grant No 3095002 to C. A. Villagra, US National Science Foundation grant DEB-0317217 to R. A. Raguso and Contracts ICM P02-005 and PFB-23 to the Instituto de Ecologfa y Biodiversidad. Finally, we are thanks to Shmutzer family and BioParque Puquen staff, Los Molles, V Region, Comuna de La Ligua, Chile for their hospitality and involvement.
文摘The study of multi-modal communication has only recently been extended to innate and learned interactions between flowers and their animal visitors, and usually only to pollinators. Here we studied the relevance of floral scent and visual display of a night blooming, putatively hawkmoth-pollinated plant Oenothera acaulis （Onagraceae） in the attraction of non-native cockroaches Blatta orientalis （Blattodea： Blattidae）, which function as facultative floral larcenists in coastal habitats of central Chile. We experimentally decoupled visual （corolla） and olfactory （fragrance） stimuli by presenting paper corollas and green mesh bags, with or without a freshly-picked natural flower inside. We then contrasted the behavioral responses of roaches in these treatments with those to the natural combination of traits in actual flowers and their respective control treatments, measuring the roaches＇ frequency of first visits, mean and total residence time spent in each treatment. The roaches primarily used olfactory cues when approaching O. acaulis flowers at two biologically relevant spatial scales. In addition, the presence of conspecific roaches had a strong influence on recruitment to the experimental arena, increasing the statistical differences among treatments. Our results suggest a primacy of floral fragrance over visual stimuli in the foraging responses of B. orientalis. Olfactory cues were necessary and sufficient to attract the roaches, and the visual cues presented in our manipulations only marginally increased their attraction within a 20 cm diameter of the stimulus. The full spectrum of floral visitation behavior was not elicited by the artificial flowers, suggesting the need for additional tactile or contact chemosensory stimuli not provided by paper. Although the nitrogenous scent compounds that we found in O. acaulis flowers are almost exclusively found in hawkmoth-pollinated flowers, the attractiveness of these compounds to a non-native, facultative flower-visiting insect indicates that they do not function as pollinator-specific signals for hawkmoth attraction .
