Post by nomad on Jul 11, 2013 9:30:03 GMT -8
Although the English name of Brown Hairstreak suggest a dour species, this really is a beautiful butterfly especially when fresh. This species is one of the most elusive European butterflies and to obtain good specimens early collectors would beat the blackthorn bushes for the larvae. I have had the pleasure of studying this uncommon species in its favourite habitat of green lanes lined with old blackthorn hedges and an adjacent open area with blackthorn thickets. This is a late summer butterfly, with the males usually appearing in mid August and the females reaching a peak towards the end of that month and in early September.
Thecla betulae spends much of its time sitting, mating and feeding on honeydew at the tops of Ash trees. The hairstreaks usually congregate on one particular Ash tree which is known to lepidopterists as a master tree. One such tree exists in the locality that I have described. Sitting under this tree I have often observed several Brown Hairstreaks flitting and basking in the upper canopy. Only when honeydew is scarce will the males descend to feed on nearby creeping thistle and bramble but even then they are rarely encountered. When I have been lucky enough to find the males feeding, I notice after they have finished they will often land on a nearby leaf and clean themselves using their front forelegs. The females descend later and fly erratically at breath neck speed along the hedgerows, occasionally stopping to feed on bramble flowers or rarely as happened in 2012 on ripe blackberries [see photography section]. In between ovi- positing and feeding, the females may bask with her wings open in weak sunlight providing a rare photo opportunity. The females are particularly beautiful with her white streaked deep orange underwings. The males are a paler orange-brown but are nonetheless attractive. It remains to be seen what the effect of the virulent Ash die back disease which is sweeping Britain and may kill most of our Ash trees will have on the ecology of this butterfly.
Shown below are photographs of this Thecla betulae that were taken by myself in 2012 and some specimens which includes some rare aberrations.
Female.
Male
Thecla betulae spends much of its time sitting, mating and feeding on honeydew at the tops of Ash trees. The hairstreaks usually congregate on one particular Ash tree which is known to lepidopterists as a master tree. One such tree exists in the locality that I have described. Sitting under this tree I have often observed several Brown Hairstreaks flitting and basking in the upper canopy. Only when honeydew is scarce will the males descend to feed on nearby creeping thistle and bramble but even then they are rarely encountered. When I have been lucky enough to find the males feeding, I notice after they have finished they will often land on a nearby leaf and clean themselves using their front forelegs. The females descend later and fly erratically at breath neck speed along the hedgerows, occasionally stopping to feed on bramble flowers or rarely as happened in 2012 on ripe blackberries [see photography section]. In between ovi- positing and feeding, the females may bask with her wings open in weak sunlight providing a rare photo opportunity. The females are particularly beautiful with her white streaked deep orange underwings. The males are a paler orange-brown but are nonetheless attractive. It remains to be seen what the effect of the virulent Ash die back disease which is sweeping Britain and may kill most of our Ash trees will have on the ecology of this butterfly.
Shown below are photographs of this Thecla betulae that were taken by myself in 2012 and some specimens which includes some rare aberrations.
Female.
Male
