Hypena crassalis (Fabricius, 1787)

Description: Wingspan 28-34 mm. The sexes are dimorphic. Forewings in the male are rich purple brown to the postmedian area with a fine white line and a dark apical streak. The female is more of a chocolate brown, becoming white towards the termen. There is a small white streak running from the basal area along the dorsal aspect of the wing and a small dark brown apical streak. There is also a row of brown spots which can be clearly seen on the pale white band. Hindwings dark brown in male paler in female with darker veining and a well-defined discal spot.

Key Identification Features:

• White markings on the forewings
• White dorsal streak
• Small apical streak
• Dark hindwings and small discal spot

Sets:

Flight Period: Mid-June to mid-August.

Status: First recorded in June 1988 at Crom, Fermanagh. Its detection in Fermanagh subsequently led to its discovery near Fivemiletown, Rehaghy and Crockacleaven Lough in Tyrone. It has also been found recently further east in Gosford Forest Park and the Argory, Armagh and Bohill in Down

Ecology: A species associated with open woodland where its foodplant (Bilberry Vaccinium myrtillus) is common. Adults come to light in very small numbers; they rest by day among ground vegetation or on tree trunks and are easily disturbed, flying erratically for some distance before settling again. The larvae feed during August and September on Bilberry and, possibly, Heather Calluna vulgaris.

World Distribution: Eurasiatic; found mainly in central and northern Europe from northern Spain to Fennoscandia.

Bradley & Fletcher number: 2476 Agassiz number: 72.007

Additional information:

UK Moths account

Caterpillar: