Pupae Pupation, a stage that lasts about two weeks, occurs under silk strands at the base of the food plant. The chrysalis is olive green/brown and formed on the ground, where it is attended by ants. Ants may aid in protecting the pupa and may bury it to protect it from predators. Adults The male, with a bluer color, is more conspicuous than the female, which has brown upperwings. Males fly farther distances in search of territories that have fertile females. Females fly lower and search for nectar and places to lay her eggs. Wing span ranges from . When the sexes meet, copulation occurs immediately, usually without any courtship ritual. Physiology Vision Visual systems in butterflies are highly diverse and their color vision abilities have only begun to be explored. To see color, P. icarus uses a duplicated blue opsin in conjunction with its long-wavelength opsin LWRh. This enables the common blue to see color in the green part of the light spectrum extending up to . There is also a difference between the dorsal and ventral eye-shine of P. icarus, with the dorsal retina dominated by yellow-reflecting ommatidia and the ventral exhibiting yellow and red-reflecting ommatidia. P. icarus is able to use color vision and distinguish between yellow of and blue of , but is not able to distinguish between yellow and red of 640 nm. See also List of butterflies of Great Britain References External links Polyommatus Butterflies of Asia Butterflies of Europe Coprophagous insects Butterflies described in 1775