Flowering plants are able to make flexible use of their
scents. If the focus is on pollination they attract insects with the scent of
their flowers. If they are infested with parasites, they reduce the release of
floral scents which then attracts more beneficial partner insects for their
defence. This has been demonstrated by a Swiss-Italian team led by evolutionary
biologists from the University of Zurich using a plant that is closely related
to rapeseed.