Novice Lepidopterist Mike Robinson continues to ‘tick off’ the butterflies of Bexley with his camera. On July 22nd he was lucky enough to spot this White-letter Hairstreak (Satyrium w-album) feeding on a Creeping Thistle head. This is one of the most difficult species to photograph since although they sometimes come down to nectar on flowers, they spend most of their time in the canopy of Elm trees and are consequently likely to be overlooked or, if seen in flight, usually disappear from view upon landing. Some good fortune is therefore required.
White-letter Hairstreak, showing why the scientific name includes the epithet w-album (white w). Pictured at Footscray Meadows by Mike Robinson.
Up until a few years ago the woodland at Footscray Meadows was the only place where this species was thought to exist in the Borough, and it had its own Bexley Council Biodiversity Action Plan, but this was one of a number scrapped due to a lack of any implementation.
Some targeted searching of Elm-rich areas was then done by myself, and it was soon found at Moat Lane in Slade Green, Barnehurst Golf course, and by Bursted Woods. There are a number of other sites that still have lots of sizeable Elm ‘suckers’ that I have only watched occasionally and all too briefly, and where a more consistent effort might well turn it up, such as Burnt Oak Lane and Lamorbey Park in Sidcup, and the north margin of Franks Park in Erith.
Although the caterpillars feed exclusively on Elms, the species has fortunately survived the massive depradations of Dutch Elm disease.
Mike is currently working on getting some good shots of Purple Hairstreak, which spends its time flitting around the upper parts of Oak trees, mainly in the evening. This species is widely distributed in Bexley, seemingly occurring almost anywhere with a few mature Oaks. The glade within the Warren, Bexleyheath, is a good place to see them flying relatively low down, as one end of it catches the evening sun in summer.
Chris Rose
