Scotopteryx mucronata, the lead belle, is a species of moth in the Geometridae family. It is found in most of Europe, Turkey, Ukraine, West Siberia. The wingspan is 30–38 mm. The ground colour of the forewing is grey to brownish grey in colour. There is a distinctive brown median band and bounded by darker cross lines. The centre (discal) spot is usually drop-shaped. However, the pattern is variable. The rear wing is greyish. Very similar to Scotopteryx luridata q.v. Adults are on wing from May to June in one generation per year.