Common blue butterfly

Description

The common blue is a small butterfly of the family Lycaenidae, among the most widespread and common in Europe. It shows marked sexual dimorphism: the male has the upperside of its wings a bright, vivid blue edged with dark brown, while the female is mostly brown with a dusting of blue and a row of orange lunules along the margin. The underside, greyish-brown with black spots ringed in white and orange markings, is similar in both sexes.

Habitat and distribution

It occurs throughout Eurasia and North Africa. It frequents open, sunny, flower-rich habitats: meadows, waste ground, roadsides, clearings and gardens. It is a highly adaptable species, found from lowlands to the mountains.

Life cycle

The caterpillars feed on leguminous plants, particularly bird's-foot trefoil and related species. Like many lycaenids, the larvae have a mutualistic relationship with ants: they produce sugary secretions the ants are fond of, and in return receive protection from predators.

Behaviour

The adults fly from spring to late summer, in several generations a year, feeding on flower nectar. It is a lively but unwary butterfly, readily settling to bask in the sun with wings spread.

Conservation

It is a common, unthreatened species, but like all grassland butterflies it suffers from the loss of flowery habitats and pesticide use. Untreated meadows rich in legumes favour its presence.