Yet these are presumably distinguishable to insects. Some flowers have been recorded as having fluorescent nectar, however, butterfly pollinated flowers have not been found to use this tactic. Most blue light receptors of plants are reactive to long wave ultraviolet, to around 370nm. In general, ultraviolet is not thought to have a significant effect on plants. Adaptive features, to protect against damage from ultraviolet radiation, are likely to be present in plants growing at high altitudes.
Bees are very widely studied insects with regard to their visual system.
This has been interpreted in the trichromatic theory. It occurs mostly in the upper lenses of the compound eye, and is most likey used for spatial orientation in overcast conditions. Ultraviolet patterns and behavioral effects of colour on butterflies Human vision Butterfly vision simulation Ultraviolet Fig.5 Butterfly vision simulation of Cleopatra - Goneopteryx cleopatra. Follow link to larger versions. Quick recognition during courtship is important, as they normally rely on a rapid, erratic escape flight to defend against predation.