Hadena caesia

The wingspan is 32–37 millimetres (1.3–1.5 in). Forewing blue grey, with a furry look, caused by dusky grey irroration; both folds tinged with fulvous; lines and markings often indistinct; upper stigmata pale, with yellow scales in their annuli; a dark antemedian band widened to inner margin and a less prominent dark submarginal cloud; a small dark blotch at middle of costa; hindwing dark fuscous, paler towards base; — manani Gregs. from the Isle of Man and the Irish coast, is uniformly darker slate colour; — ab. nigrescens Stgr., from the Pyrenees, Alps, and Mts. of Scandinavia is much darker, the forewing suffused with black; on the other hand [now full species Hadena clara] Stgr., from Armenia and Asia Minor, has the forewing greyer, with a pinkish tinge; the median area paler.^[1]

Adults are on wing from June to August.^[2]

Larva brownish ochreous, freckled with darker; a dorsal series of V-shaped marks; subdorsal line darker. The young larvae feed on capsules of various Silene species (including Silene nutans and Silene vulgaris).^[3] Later, they feed on the leaves. They overwinter as a pupa.

• ssp. caesia (Denis&Schiffermüller, 1775) (Alps)
• ssp. abruzzensis (Draudt, 1934) (Apennine Mountains)
• ssp. ostrogovichi (Hacker, 1989) (Carpathian Mountains)
• ssp. bulgarica (Boursin, 1959) (Bulgaria)
• ssp. xanthophoba (Schawerda, 1922) (Balkan Peninsula)
• ssp. mananii (Gregson, 1866) (Great Britain, Ireland and the Isle of Man from where it is named)
• ssp. frigida (Zetterstedt, 1839) (southern Fennoscandia)
• ssp. grisea (Hospital, 1948) (mountains of northern Spain)
• ssp. revolcadorensis (Calle, 1983) (the Region of Murcia)
• ssp. castiliana (Reisser, 1935) (Castile region)