Common Blue Polyommatus icarus


The Common Blue is the most widely distributed of the British blues and is commonly seen in a wide range of grassy habitats, including meadows, dunes, heaths, roadside verges and gardens.


The male is violet-blue with a fine black edge and white wing margins. Females also have white wing borders, and vary from the usual brown form with a hint of blue to those which are extensively blue varieties, all with orange marginal spots. The underside of the hind wings lacks the vertical twin spots of the Brown Argus.

Flight times

Generally double-brooded, it is on the wing in May and June, and again in August and September.

Food plants

Eggs are laid singly on a variety of leguminous plants, but it favours Bird's-foot-trefoil, Restharrow and Black Medick.

Common Blue
Common Blue - © Simon Jenkins.

Distribution Maps

Common Blue distribution map 2005-09
Common Blue distribution map 2010-14
Common Blue distribution map 2015
2015 Summary
No of tetrads 492
First sighting 28/03/2015
Last sighting 11/10/2015
Common Blue distribution map 2016
2016 Summary
No of tetrads 353
First sighting 05/05/2016
Last sighting 23/10/2016

Photo Gallery