260 Polia hepatica (Silvery Arches)

73.260 Polia hepatica (Silvery Arches)

fw: 21-25mm (Waring & Townsend), ws: 43-52mm (MBGBI9); Jun-Jul; birches (Betula spp), sallows (Salix spp); NS-B in scrubby woodland on moor and river valleys locally in Scotland, on the heaths of Surrey, Hampshire and Berkshire and at scattered locations elsewhere in Britain; suspected occasional migrant.
Synonym: Polia trimaculosa (Waring & Townsend)

Polia hepatica (Silvery Arches) §1 male

ID: Both P.hepatica and P.nebulosa (Grey Arches) have a whitish to grey forewing (P.nebulosa can be blackish), with distinct, dark-outlined, pale oval, kidney ann dart marks. P.nebulosa has a more strongly curved costa especially in the apical 1/3. In P.hepatica the subterminal line is edged proximally with (3) black dashes at costal and dorsal ends and at ~1/3 from costa; P.nebulosa has interneural black arrow marks pointing basally from the subterminal line, the most prominent of which is at the dorsal end. In P.hepatica the grey thorax has a central reddish tuft; in P.nebulosa the thoracic tuft is grey, concolorous with the thorax. P.bombyina (Pale Shining Brown) is similarly marked but shining reddish-brown.

Dissection

Male genitalia

Page published 12/10/2016 (§1)