Purple Hairstreak Favonius quercus
Formerly Neozephyrus quercus
Another tree-top dweller, breeding in oak trees and much more widespread than the Brown Hairstreak though at least as hard to see well. The purple sheen is not always apparent, especially in males which can look black from some angles, though in both sexes the underwing is a silvery grey with a distinct white hairstreak line.
Images L-R: male; female; larva hibernating amongst oak buds.
Flight Period: June - September