Volume 19, Issue 16, Pages 1368-1372 (August 2009) Orchid Mimics Honey Bee Alarm Pheromone in Order to Attract Hornets for Pollination  Jennifer Brodmann, Robert Twele, Wittko Francke, Luo Yi-bo, Song Xi-qiang, Manfred Ayasse  Current Biology  Volume 19, Issue 16, Pages 1368-1372 (August 2009) DOI: 10.1016/j.cub.2009.06.067 Copyright © 2009 Elsevier Ltd Terms and Conditions

Figure 1 Dendrobium sinense Flower and Vespa bicolor Forager D. sinense flower (A) and V. bicolor forager with pollinia stuck onto the thorax (B). (Photographs by J.B. and S.X.-q.) Current Biology 2009 19, 1368-1372DOI: (10.1016/j.cub.2009.06.067) Copyright © 2009 Elsevier Ltd Terms and Conditions

Figure 2 Approaches of Hornets to Various Odor Samples Tested in a Flight Cage Comparison of the attractiveness of the scent from an orchid flower and honey bee dummies impregnated with flower extract or pentane solvent in a flight cage (Mann-Whitney U test + Benjamini-Hochberg correction [28], p ≤ 0.05, n = 6). Bars represent median number of approaches ± standard error of the mean. Different letters indicate significance differences between the test groups. Current Biology 2009 19, 1368-1372DOI: (10.1016/j.cub.2009.06.067) Copyright © 2009 Elsevier Ltd Terms and Conditions

Figure 3 Electrophysiologically Active Compounds Electrophysiologically active compounds in the flower extract of D. sinense (A) and comparison of the electrophysiologically active compounds of a flower extract of D. sinense and the body surface extract of an Apis cerana forager (B). Simultaneous recordings of gas chromatography (flame ionization detector [FID]) and electroantennographic detector (EAD) signals obtained with flower extracts of D. sinense via the antenna of a V. bicolor worker were performed on a polar DB-WAX capillary column. Benzyl acetate, benzyl alcohol, octadecan-1-ol, eicosan-1-ol, and (Z)-11-eicosen-1-ol were electrophysiologically active in the flower extract; octadecan-1-ol, eicosan-1-ol, and (Z)-11-eicosen-1-ol also were detected in the A. cerana body surface extract. Current Biology 2009 19, 1368-1372DOI: (10.1016/j.cub.2009.06.067) Copyright © 2009 Elsevier Ltd Terms and Conditions

Figure 4 Attraction of Hornets to Various Odor Samples Comparison of the attractiveness of the odor from an orchid flower, the flower extract, the synthetic mixture of the EAD-active compounds of the flower extract (s. D. sinense), and (Z)-11-eicosen-1-ol in a Y tube olfactometer (sign test, ∗p ≤ 0.05, ∗∗p ≤ 0.001, n = 20 for each test). Current Biology 2009 19, 1368-1372DOI: (10.1016/j.cub.2009.06.067) Copyright © 2009 Elsevier Ltd Terms and Conditions