Colias palaeno

Colias palaeno, known by the common names moorland clouded yellow, palaeno sulphur, and pale Arctic clouded yellow, is a butterfly in the family Pieridae. Subspecies include: Colias aias is treated as a full species by some authors. Colias palaeno is a Holarctic species, widespread through Asia, Europe and North America. It is present in central and northern Europe from eastern France to the Baltic States and northern Sweden, Norway, Finland and to the eastern Europe, then in eastern Siberia, in the Chukchi Peninsula, in Japan and in northern areas of North America. This species inhabits various types of moorland, forest meadows, open coniferous forests and open areas which may contain scrub. In the southern areas of its range it is a high alpine species reaching an elevation over 1,500 metres (4,900 ft) above sea level, but it can be found on upland bogs at an elevation of about 1,000 metres (3,300 ft). Though the species is normally restricted to these habitats, occasionally it is found far from suitable breeding grounds. Colias palaeno has a wingspan of 46–50 millimetres (1.8–2.0 in) in males, of 50–52 millimetres (2.0–2.0 in) in females. Upperside of male pale yellow with blackish brown distal margins, pale-centred dark middle spot to the forewing and light middle pot to the hindwing; fringes red. Underside of forewing pale yellow with white-centred dark middle spot,the costal and distal edges being red; hindwing yellow, strongly dusted with fuscous, the large middle spot being mother-of-pearl colour, and the fringes red. The female has a white ground colour above, the underside of the forewing being white proximally, yellow at apex, the hindwing being somewhat paler in the female than in the male. The larva is sea-green, velvety, bearing minute black dots; a lateral stripe bright yellow edged with black beneath, below the same the white black-edged spiracles; underside and abdominal legs dull green, thoracical legs yellowish, head green. The Pupa is greenish yellow, the back being strongly convex. It is a univoltine species, flying from June to August. As most Colias-species, Colias palaeno is an avid flyer. The larva is found on bog bilberry (Vaccinium uliginosum), on Vaccinium myrtillus and on Vaccinium caespitosum.