The swallowtail butterfly, Papilio nireus, has a beautiful green fluorescent wing band. The wing fluoresces at a wavelength that is in tune with the principle light receptor pigment in the compound eyes of adult butterflies. Producing an intense fluorescence is key to successful mate attraction.
The green color is produced by a pigment that is maximally stimulated by light at 420 nm and fluoresces at 505 nm. The pigment is arranged in a photonic crystal slab below the outer…
Source: Living With Insects Blog