Blues, coppers and hairstreaks · Denmark

White-letter hairstreak

Satyrium w-album

White-letter hairstreak is present here in Denmark. Wing span: 26-33 mm. White-letter hairstreak has only one generation per year, with flight times ranging from late June to August. Like Purple Hairstreak, its presence is determined by its host plant.

Status in this countryLocally present in DenmarkLC (Least concern)

Flight period

White-letter hairstreak has only one generation per year, with a flight period from late June to August.

Habitat

Like Purple Hairstreak, its presence is determined by its host plant. As long as there are sunlit elm trees, you can find white-letter hairstreak.

Identifying features

Wingspan: 26–33 mm. The upperside is dark brown.

Similar species

May be confused especially with black hairstreak (Satyrium pruni) and ilex hairstreak (Satyrium ilicis), both extinct in Denmark. The distinguishing features are the W-shaped marking and the black line separating the outer-margin area at the hindwing tip.

Distribution

Found mainly in eastern Jutland, on Zealand and the islands. The species has declined.

Biology

All four life stages (egg, larva, pupa, and imago) live in elm trees. After overwintering, the egg hatches, and the larva feeds on flower buds and manna.