70.040 Scotopteryx mucronata (Lead Belle)
fw: 15-19mm; May-Jun; gorse (Ulex), broom (Cytisus scoparius), petty whin (Genista anglica), dyer's greenweed (Genista tinctoria); local on acid heath and moor - ssp umbrifera in SW England & S coast of Wales, ssp scotica N.Wales, N.England and Scotland
Scotopteryx mucronata (Lead Belle) §7 male
ID: Very similar to S.luridata (July Belle) and may be indistinguishable on external features, all those mentioned below being somewhat variable and relative. S.mucronata flies earlier (mid-May to mid-Jun vs Jun-Aug); is more confined to acid heath and moor (where S.luridata also occurs); typically has a lighter grey ground colour; zigzag subterminal line better defined; central forewing spot tear-shaped (smaller, rounded in S.luridata); spot placed midway between 2nd & 3rd lines (nearer 2nd line in S.luridata).
Male genitalia: In both species the valva has a free costa and a long sacculus with a bifid apex. In S.luridata the costa is of fairly even width through most of its length and then tapers at the apex; in S.mucronata the costa is narrow at its base, expands into a broad central section and then narrow again at the apex. In S.luridata the cornutus is narrowed at both ends and without obvious serration of its edges; in S.mucronata it is distinctly broader at the basal end and narrows towards the apex, and one edge is distinctly serrate.
Male genitalia: In both species the valva has a free costa and a long sacculus with a bifid apex. In S.luridata the costa is of fairly even width through most of its length and then tapers at the apex; in S.mucronata the costa is narrow at its base, expands into a broad central section and then narrow again at the apex. In S.luridata the cornutus is narrowed at both ends and without obvious serration of its edges; in S.mucronata it is distinctly broader at the basal end and narrows towards the apex, and one edge is distinctly serrate.
§1 Bampton Grange, Cumbria; 14/06/2017; female; fw 14.2mm; netted by day
§2 Tulloch Moor, Perthshire; 27/05/2025; male; fw 16.7mm
§3 Knipe Moor, Cumbria; 19/05/2025; male
§4 Knipe Moor, Cumbria; 19/05/2025; male
§5 Knipe Moor, Cumbria; 19/05/2025; male
§6 Knipe Moor, Cumbria; 19/05/2025; male
§7 Knipe Moor, Cumbria; 19/05/2025; male
§8 Knipe Moor, Cumbria; 19/05/2025; male
All images © Chris Lewis
§2 Tulloch Moor, Perthshire; 27/05/2025; male; fw 16.7mm
§3 Knipe Moor, Cumbria; 19/05/2025; male
§4 Knipe Moor, Cumbria; 19/05/2025; male
§5 Knipe Moor, Cumbria; 19/05/2025; male
§6 Knipe Moor, Cumbria; 19/05/2025; male
§7 Knipe Moor, Cumbria; 19/05/2025; male
§8 Knipe Moor, Cumbria; 19/05/2025; male
All images © Chris Lewis
Page published 16/01/2018 (§1) | §2 added 02/08/2025 | §3-8 added 07/11/2025
