Ecliptopera silaceata

The nearly elliptical white marking in the forewing discal field is a reliable distinguishing feature from similar species, though absent in some specimens. Distinguished from Ecliptopera capitata by duller colours, more arrow spots in post-discal region, and brown (not yellow-orange) head and thorax. Distinguished from Lampropteryx suffumata by more distinct bowed spots at outer edge that do not extend beyond the wavy line, less jagged transverse lines, and less brown ground colour. Distinguished from Eulithis prunata by less brownish ground colour and less serrated outer transverse line.

Wingspan 23–27 mm; forewing length 13–17 mm. Forewings with dark grey basal region bordered by a light band containing dark stains. Broad discal region black-brown, often with a nearly elliptical white marking centrally. Marginal area brown with prominent arrow patches; two or three distally facing peaks continue as orange strokes toward the outer edge. Below apex, dark arch stains and white wavy line at outer edge. Hindwings white-grey with bright crosslines and small black discal spot. Head, thorax, and abdomen brown. Two main colour forms differ in extent of white markings breaking the central forewing band. Male with abdomen tip curled upward when at rest. Larva long and thin, variable green or flesh-colour; thoracic and last four abdominal segments with red or blackish dorsal line; middle segments with blackish dots; venter with white line, sometimes pink-edged.

Semi-shaded areas in deciduous and mixed forests, young forest plantations, and heaths. Occurs wherever larval foodplants (willowherbs) are present, including varied open and wooded habitats.

Europe (including British Isles, north to Arctic Circle, south to Caucasus), east through Russia to Altai and Vyatskoye regions, and parts of North America. Common across Britain and Ireland; absent from Shetland.

Two generations in most of range: May to July and August to September. Third generation possible in southern parts of range depending on latitude and summer temperatures. Flight season varies geographically.

Larvae feed primarily on willowherbs (Epilobium spp.).

• Epilobium spp. - larval foodplantwillowherbs

Usually two generations annually; sometimes three in favourable conditions. Overwinters as a compact, brownish-green pupa. Larval development on willowherbs; pupation in soil or leaf litter.

Male adopts distinctive resting posture with abdomen tip curled upward. Adults active in crepuscular and nocturnal periods. Two colour forms present in populations, not seasonally determined.

Subject of genomic sequencing (Wellcome Sanger Institute, 2024). Monitored in standard moth recording schemes. No economic significance.

• Ecliptopera capitataBrighter colours, fewer arrow spots in post-discal region, yellow to orange-brown head and thorax (vs. brown in silaceata)
• Lampropteryx suffumataBowed spots at outer edge more indistinct and extend beyond wavy line; transverse lines more jagged; ground colour more brown
• Eulithis prunataMore brownish ground colour; outer transverse line more serrated

• Geometridae
• Larentiinae
• moth
• Palearctic
• Nearctic
• bivoltine
• willowherb feeder

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• The genome sequence of the Small Phoenix, Ecliptopera silaceata (Denis & Schiffermüller, 1775).