White-letter Hairstreak Satyrium w-album

The White-letter Hairstreak (Satyrium w-album) is a secretive butterfly named for the distinctive 'W'-shaped white line on its hindwing underside. It is closely associated with elm trees, and the catastrophic spread of Dutch elm disease from the 1970s onwards caused severe population crashes across the UK. In Suffolk, the species persists where mature elms survive – particularly English elm in hedgerows and woodland edges, which remains more widespread here than in many other counties. Adults spend much of their time high in the canopy, making them easy to overlook. July is the best month to search for this elusive species. Image: © iwo2022, iNaturalist

Find out more: iNaturalist, Suffolk Wildlife Trust, Butterfly Conservation, UK Butterflies