White Letter Hairstreak
Latin name: Satyrium w-album
The white letter hairstreak butterfly is in a family that includes hairstreaks, coppers and blue butterflies. This is an elusive butterfly that mainly flies in or above the trees canopy. However, the best chance of seeing it in the Dales would be on a still sunny day, at lower altitudes in July feeding on privet and bramble flowers below English and Wych Elm in deciduous woodland or by isolated trees in lower Wharfedale. It has one generation each year and lays its eggs on Elms.
This species experienced significant declines across the country during the 1970s when the main foodplant were reduced by Dutch Elm Disease. Populations are beginning to increase in many areas. Within the National Park this species is known from a small number of sites in lower Wharfedale.