About Scopula immutata (Linnaeus, 1758)
Scopula immutata (Linnaeus, 1758) is a moth species. Its typical wingspan measures 24–27 millimetres (0.94–1.06 in), and its forewings are 12–13 millimetres (0.47–0.51 in) long. For the second generation in southern parts of its range, and for moths from the northern portion of its range, wingspan can reach only 19–23 millimetres (0.75–0.91 in). The moth’s base wing colour is silk white, with variable intensity of yellow dusting, particularly noticeable in males. Drought and high temperatures during pupal development produce more yellowish moths with more defined patterns. Its wavy crosslines range in colour from yellowish and ochreous to light brown, and have a fine scattering of black scales. There are typically four crosslines, plus one wavy marginal line that is often wide and blurred. Discal flecks are always present, but can be much weaker on the forewings. Marginal stains occur occasionally, and are small and inconspicuous when present. For further taxonomic detail, see Prout. It is similar in appearance to Scopula floslactata, but can be distinguished by its more rounded forewings and black discal spot. The egg of this species is almost perfectly cylindrical, with only slightly rounded ends. It has around 15 prominent longitudinal ribs, plus very fine transverse ribs, numbering 15 to 18. It is a delicate greenish-yellow when first laid, and turns pale pink with scattered crimson spots after two days. The larva is rather slender, nearly cylindrical, and tapers toward the head, with distinct subsegmentation. It is grey-brown, with a fine pale medio-dorsal line that has fine dark edges thickened into black dashes at the ends of each segment. It has an ill-defined dark supra-spiracular line and a rather pale lateral stripe that holds the black spiracles. The pupa is pale brown, with more greenish wing cases. In western Europe, the moth flies in one generation from June to August. The larvae feed on meadowsweet and valerian. Adults rest by day among tall rank grass, and are easily disturbed from their resting spots. This is a typical temperate to boreal Palearctic moth species. In Europe, its range extends from the west coast of France and the British Isles east to the Urals. To the north, it reaches as far as central Scandinavia, and it ranges south to central Italy and southern Bulgaria. The southern Bulgarian population is isolated from the main species range, and is limited to higher elevation areas. There are also small, isolated populations recorded in northern Portugal and north-eastern Spain, and the species has been reported from Corsica and Sardinia. These outlying records have not yet been confirmed. Outside of Europe, the species spreads east across the Caucasus, Kazakhstan, southern Siberia, Mongolia, the Russian Far East, and Sakhalin. This moisture-loving species occurs in humid forests, swamps, bogs, wet meadows, and along rivers. In the Alps and southern Europe, it can be found at elevations up to 1,200 metres (3,900 ft), and rarely reaches even higher elevations, with a maximum recorded elevation of 1,850 meters.
