THE SPECTRUM OF BLUES
There are six other blue butterflies in Britain as well as the closely related Brown Argus and Northern Brown Argus. Of these, only the Holly Blue is anywhere near as common and widespread as the Common Blue. Found in much of England and Wales, and parts of Northern Ireland, it is more often in gardens than grasslands. Holly Blues also have two generations, the first of which lays its eggs on holly and the second on ivy, so it is often found in churchyards. The other five blues, Adonis, Silver-studded, Chalk Hill, Large and Small, are far more localised. Apart from the Silver-studded, which has an outlying population in North Wales, they can only be seen on the chalk and limestone downlands of southern England. Even here, they are often confined to a few nature reserves, where the vegetation is specially managed for their needs. They usually emerge in June, July and August. All lay their eggs on specific food plants for their caterpillars, most of which are in decline as so much land is being lost to intensive farming, roads and housing. Of all the blues, the Adonis, named after an especially handsome Greek god, is the most striking. The males are an intense shade of blue, contrasting with the Chalk Hill blue’s more subtle powder-blue hue. The Silver-studded blue has metallic blue spots on its underwings, whereas the Small Blue is a very dark blue. As its name suggests, it is Britain’s smallest butterfly. The Large Blue, which in reality is only a little larger than the Common Blue, became extinct in Britain in 1979. However, thanks to discoveries about its complex life cycle and habitat needs, and huge efforts on the part of scientists and conservationists, it has been successfully reintroduced as a British breeding species in Somerset and Gloucestershire. Crowds of butterfly enthusiasts gather there in June and July to catch sight of it.