Bright iridescent patches are honest signals!

Males butterflies in the family Lycaenidae, the so-called Blues, typically have brightly coloured, iridescent colours on the upper (dorsal) surfaces of their wings. Vivid blue iridescence such as this on the Purple Sapphire (Heliophorus epicles) shown here, is usually to do with courtship and mate recognition. The brightly coloured, iridescent males rely on so-called, structural colouration (described below), which…