As with most species, male butterflies emerge first, usually in mid-July, and if the weather is suitable with opportunities for regular nectaring, will live for seven weeks. Quite often though, August is the only month one can be sure of seeing the Chalkhill Blue. It is confined to southern England particularly over the north and south downs, the Wiltshire downs, Chilterns, Cotswolds, Isle of Wight and Purbeck. It is very rare in south-west England and East Anglia.
The males are very obvious in flight or when sitting resting on plants as their powder blue colour and large size make them quite unique.
The male has a pale powder blue upper wing surface which may vary from a very pale silvery blue through to a greenish tinted blue according to locality, although it always has the outer wing margin of a blackish band with six or seven partly submerged black dots to each wing, completed by a narrow white outer margin.
The female is dark brownish-black or soot colour, and her rows of black dots have very slightly orange-tinted surrounds, followed by a dingy white outer border.
The under sides of both sexes are respectively greyish and in the female pale brownish. Both have 10 black, white-circled dots on the forewings, and 12 on the hind wings, then a border of black dots, faintly orange-circled in the female.
This year looks like being a good year for the Chalkhill Blue....a couple of weeks ago I visited a site where I know there's a good breeding colony and you can be assured of seeing them in reasonable numbers, but I was greeted by the spectacular sight of large numbers taking nutrients from, of all things, cow pats! I counted at least 30 individuals on one cow pat alone, and there were more on the surrounding cow pats!
And then yesterday I visited a new site (for me) less than three miles from home where they were so numerous that it was difficult not to step on them!
Many were busy making sure that there's a great prospect of a good emergence for next year!