|Dötterl, S; Füssel, Ulrike; Jürgens, A; Aas, G: 1,4-Dimethoxybenzene, a floral scent compound in willows that attracts an oligolectic bee, Journal of Chemical Ecology, 31(12), 2993-2998 (2005)|
Many bee species are oligolectic and collect pollen for their larvae only from one particular plant family or genus. Here we identified flower scent compounds of two Salix species important for the attraction of the oligolectic bee Andrena vaga, which is collecting pollen only from Salix. Flower scent was collected using dynamic-headspace methods from Salix caprea and S. atrocinerea, and the samples were subsequently analyzed by coupled gas chromatographic-electroantennographic detection (GC-EAD) in order to detect possible foraging kairomones of Andrena vaga. EAD active compounds were identified by gas chromatography coupled to mass spectrometry. Both Salix species had relatively similar scent profiles and the antennae of male and female bees responded to at least 16 compounds, among them different benzenoids as well as oxygenated monoterpenoids and sesquiterpenoids. The strongest antennal responses were triggered by 1,4-dimethoxybenzene and in field bioassays this benzenoid attracted females of Andrena vaga at the beginning of its flight period, but not at the end.