About Selenia dentaria (Fabricius, 1775)
This species, Selenia dentaria (Fabricius, 1775), has a wingspan ranging from 28 to 40 mm. Its wings have scalloped edges, and the forewings bear 3 crosslines, with a dark stain at the forewing apex. Adult individuals are extremely variable in colour. The species can be distinguished by the following characteristics: a less deep excision between the radials of the hindwing, less intense colouring, enlarged costal spots at the origin of the crosslines, a median area that does not differ in colour from the distal area, and poorly developed transparent discal marks. The spring form of Selenia dentaria is large, strongly dusted with fuscous, and sometimes more olivaceous; its median and postmedian lines are darkened into a band. The form ab. illunaria Esp. is the summer generation, which is much smaller and far less irrorated than the spring form, and can sometimes be pale, and sometimes a warmer brown. The form ab. minima Strand is a dwarfed form, which is sometimes sharply marked, and frequent in Arctic Norway. The larva is orange-brown or reddish brown, sometimes with a purplish tint. The meso- and metathorax are enlarged laterally, the 4th to 5th abdominal segments are swollen and bear small dorsal humps, and the anterior segments are marked with bright orange.
