Gonepteryx rhamni Brimstone
This butterfly feeds on Rhamnus cathartica (Buckthorn) and Frangula alnus (Alder Buckthorn) neither of which grow in any quantity near home in Cheshire so I tend to see this butterfly on my travels down south or in the limestone dales of Derbyshire.
There were very few nectar bearing plants in flower following the severe winter of 2009/2010 so the butterflies had to make do with what was available: various Prunus species and Viola odorata (Sweet Violet).
Edge of Devil's Dyke, near Newmarket, Cambs, 9th April 2010
Added on 4th Oct 04, amended on Jan 26th 05, updated 26th June & Nov 6th 08.updated 12th April 2010