Posted 12th Jul 2017
Image courtesy of © Margaret Holland
Amongst our butterflies, one group will best sum up the hottest days of high summer
Picture the scene. On a south-facing downland slope, with the scent of thyme and marjoram on the air, swallows skimming low over the grass and the buzzing of grasshoppers in your ears, bright blue butterflies skip and chase across the hillside.
An incredibly rare beast, the large blue will only be found in a tiny handful of locations where it has been introduced, and the small blue flies earlier in the year. However, the other five 'blues' are all on the wing in the summer holidays. The dainty silver-studded blue is a butterfly of heathlands, where caterpillars feed on gorse amongst other plants - you could come across it while keeping an eye out for reptiles or Dartford warblers. The silvery-pale holly blue can then be seen flitting about like a twinkling silver coin in gardens and parks, where it will feed on holly and ivy.
But it is on the grasslands that the blues really come into their own. The familiar common blue, the large powder-blue chalkhill blue and the dazzling azure Adonis blues can be seen on the wing together, and in the best years on the best sites, they will appear in breathtaking numbers. So sit back on the hillside and watch the cloud of blue butterflies tumble around you.
How to do it
Butterflies are at their best on a still, sunny day. Wind or rain will therefore not be a butterfly-watchers friend. You should look out for the caterpillar's food plants and flowers where butterflies find nectar - favourites include birds-foot trefoil horseshoe vetch, rock-rose and knapweed.
Most of the blues are restricted to specific locations, primarily in the south of England. However, the common blue can be found throughout the country, while the holly blue is a frequent visitor to gardens across England and lowland parts of Wales.
The large blue was re-introduced to Daneway Banks in Gloucestershire in 2002 and this special site now boasts the largest population in the country of this rare butterfly.
Bedfordshire, Blow’s Downs
Berkshire, Wildmoor Heath
Dorset, Upton Heath
Dorset, Fontmell Down
Dorset, Tout Quarries
Dorset, Tadnoll and Winfrith
Hampshire, St Catherine’s Hill
Isle of Wight, Arreton Down
London, Hutchinson's Bank
Norfolk, Roydon Common and Grimston Warren
Suffolk, Blaxhall Common
Sussex, Ditchling Beacon
Sussex, Malling Down (Chalkhill, Adonis and common blues)
Sussex, Levin Down
Information courtesy of The Wildlife Trusts