Distinguishing the various blue butterflies can be a little tricky, especially as some are actually brown. 😀 Wilf Powell has provided some information that may help you get out in July and find some Chalkhill Blues, distinguishing them from Common Blue butterflies:

• The name of this butterfly gives you a clue about where to look for it. It is found on chalk downland in southern England and can occur in large numbers at some places in the south of Bedfordshire including Totternhoe Quarry, Dunstable & Whipsnade Downs, and Houghton Regis Quarry.
• Its caterpillars feed on a plant with small yellow flowers called Horseshoe Vetch.
• The butterflies start appearing in July and can be seen flying around until the end of August.
• The males are pale blue but the females are brown with some orange spots along the edge of the hind wing.

The other blue butterfly you might see at the same time is the Common Blue, which is a much darker blue in colour.

Here are pictures of both these blue butterflies.

Chalkhill Blue	Common Blue
Male ♂	Male ♂
Female ♀	Female ♀