Two summers ago (August) I photographed a White-letter Hairstreak in the Lynher Valley, Cornwall that was of interest to locals since it was only about the third confirmed record of the species in Cornwall in the past twenty years. Last year (first week of July) I saw another one. I'm keen this year to spend some time actively seeking the species to see if I can find more than one. Can anyone tell me the earliest dates they've seen them on the wing in areas where they are more regular? Thanks