Green-veined White

The Green-veined White (Pieris napi) is a butterfly of the Pieridae family. Appearance and distribution A circumboreal species widespread across Europe and Asia, including the Indian subcontinent, Japan and the Maghreb and North America (Many authors consider the Mustard White of North America to be conspecific with napi[1] or consider napi to be a superspecies). It is found in meadows, hedgerows and woodland glades but not as often in gardens and parks like its close relatives the Large and Small Whites, for which it is often mistaken. Like other "white" butterflies, the sexes differ. The female has two spots on each forewing, the male only one. The veins on wings of the female are usually more heavily marked. The underside hindwings are pale yellow with the veins highlighted by black scales giving a greenish tint, hence Green-veined White. Unlike the Large and Small Whites two, it rarely chooses garden cabbages to lay its eggs on, preferring wild crucifers. [edit]Life cycle and foodplants The eggs are laid singularly on a wide range of foodplants including Hedge mustard Sisybrium officinale Garlic Mustard Alliaria petiolata, Cuckooflower Cardamine pratense, Water-cress Rorippa nastutium-aquaticum, Charlock Sinapis arvensis, Large bitter-cress Cardamine amara, wild cabbage Brassica oleracea and wild Radish Raphanus raphanistrum and so it is rarely a pest in gardens or field crops. The caterpillar is green and well camouflaged.When full grown it is green above, with black warts, from which arise whitish and blackish hairs. There is a darker line along the back, and a yellow line low dow on the sides. Underneath the colour is whitish-grey. The spiracular line is dusky, but not conspicuous, and the spiracles are blackish surrounded with yellow. There is extensive overlap with other leaf-feeding larvae of Large and Small Whites in some wild populations (e.g. in Morocco).It is often found feeding on the same plant as the Orange Tip but rarely competes for food because it usually feeds on the leaves whereas the Orange Tip caterpillar feeds on the flowers and developing seed pods. Like other Pieris spp. it overwinters as a pupa.This is green in colour, and the raised parts are yellowish and brown. This is the most frequent form, but it varies through yellowish to buff or greyish, and is sometimes without markings. Habitat Pieris napi is found in damp, grassy places with some shade, forest edges, hedgerows, meadows and wooded river valleys. The later generations widen their habitat use in the search for alternative food plants in drier, but flowery places. In the Mediterranean the insect is also found in scrub around mountain streams or springs and on floodplains with Nasturtium officinale. It is found from sea level to high elevations (2500m in Central Europe, 2600 m in Italy, 3600 m in Morocco). Pieris napi Habitat.Worringer Bruch, Germany [edit]Flight times The generations vary with location, elevation and season. In Northern Europe, there are two or three generations from April to early September. In warmer areas, and in some good years there is a fourth generation. In southern Europe there are three or more partially overlapping generations from March to October.