Moorland clouded yellow

Appearance

"Colias palaeno" has a wingspan of 46–50 millimetres in males, of 50–52 millimetres 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, thoracic legs yellowish, head green. The Pupa is greenish yellow, the back being strongly convex.

Naming

Subspecies include:
⤷  "Colias palaeno palaeno" – Sweden, Norway, Finland, and Estonia
⤷  "Colias palaeno aias" Fruhstorfer, 1903 – Japan the largest form of "palaeno", the marginal band of the forewing being very broad and the underside rich green
⤷ "Colias palaeno baffinensis" Ebner & Ferris, [1978] – northern North America
⤷ "Colias palaeno chippewa" W.H. Edwards, 1870 – northern North America, may be a separate species
⤷  "Colias palaeno europome" – Belgium, Germany, Slovakia, Romania, and Ukraine
⤷  "Colias palaeno europomene" Ochsenheimer, 1808 – high altitude in the Alps. This form is somewhat larger than the nominate, the male lemon-yellow above, being below deeper yellow, as is also the female.
⤷  "Colias palaeno orientalis" Staudinger, 1892 – Kamchatka very similar to "europomene", being dark greenish on the underside of the hindwing
⤷  "Colias palaeno poktusani" O. Bang-Haas, 1934 – North Korea
⤷  "Colias palaeno sachalinensis" Matsumura, 1919 – Sakhalin
⤷  "Colias palaeno synonyma" Bryk, 1923 – Sweden, Denmark

"Colias aias" is treated as a full species by some authors.

Distribution

"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.

Behavior

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, on "Vaccinium myrtillus" and on "Vaccinium caespitosum".

Habitat

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 above sea level, but it can be found on upland bogs at an elevation of about 1,000 metres. Though the species is normally restricted to these habitats, occasionally it is found far from suitable breeding grounds.