Aglais io, the European peacock, more commonly known simply as the peacock butterfly, is a colourful butterfly, found in Europe and temperate Asia as far east as Japan. It was formerly classified as the only member of the genusInachis (the name is derived from Greek mythology, meaning Io, the daughter of Inachus. It should not be confused or classified with the "American peacocks" in the genus Anartia; these are not close relatives of the Eurasian species. The peacock butterfly is resident in much of its range, often wintering in buildings or trees. It therefore often appears quite early in spring. The peacock butterfly has figured in research in which the role of eyespots as an anti-predator mechanism has been investigated. The peacock is expanding its range and is not known to be threatened.The butterfly has a wingspan of 50 to 55 mm. The base colour of the wings is a rusty red, and at each wingtip it bears a distinctive, black, blue and yellow eyespot. The underside is a cryptically coloured dark brown or black.
There are two subspecies: A. io caucasica (Jachontov, 1912), found in Azerbaijan, and A. io geisha (Stichel, 1908), found in Japan and the Russian Far East.
The peacock can be found in woods, fields, meadows, pastures, parks, and gardens, from lowlands up to 2,500 metres (8,200 ft) elevation. It is a relatively common butterfly, seen in many European parks and gardens. The peacock male exhibits territorial behaviour, in many cases territories being selected en route of the females to oviposition sites.
The butterfly hibernates over winter before laying its eggs in early spring, in batches of up to 400 at a time. The eggs are ribbed, olive green, and laid on the upper parts and the undersides of leaves of nettle plants and hops. The caterpillars, which are shiny black with six rows of barbed spikes and a series of white dots on each segment, and which have a shiny black head, hatch after about a week. The chrysalis may be either grey, brown, or green in colour and may have a blackish tinge. The caterpillars grow up to 42 mm in length.
The recorded food plants of the European peacock are stinging nettle (Urtica dioica), hop (Humulus lupulus), and the small nettle (Urtica urens).
The adult butterflies drink nectar from a wide variety of flowering plants, including buddleia, willows, dandelions, wild marjoram, danewort, hemp agrimony, and clover; they also utilize tree sap and rotten fruit.
(latin: Inachis io)