Flower colour code

Flowers also create colours and structures that can only be perceived by insects. These light effects, such as an iridescence of the surface, are caused by special three-dimensional structures of the protective wax layer, the cuticle. However, it was previously unclear how these structures are formed and what biological processes control their development. In a new study, researchers have taken a closer look at the underlying mechanisms.

What about poppies? They are red and I see bees on them!
Poppies (Papaver rhoeas) come from southern Europe where they are originally pollinated by beetles. When poppies migrated with agriculture to northern Europe 5,000 years ago, they evolved to be pollinated by bees by having secret markings which are only visible with ultraviolet light.