Aporia crataegi
Aporia crataegi, the black-veined white, is a large butterfly of the family Pieridae. A. crataegi is widespread and common. Its range extends from northwest Africa in the west to Transcaucasia and across the Palearctic to Siberia and Japan in the east. In the south, it is found in Turkey, Cyprus, Israel, Lebanon and Syria. It is not present in the British Isles and northern Scandinavia. Subspecies. Subspecies include: Distribution and habitat. It occurs in open forest, grazing land, orchards. lanes, gardens, meadows and thickets throughout most of Europe, temperate Asia, Korea, and Japan. This species is extinct  in the British Isles. Description. The black-veined white has a wingspan of . Females are commonly larger than males. The upperside of both forewings and hindwings is a translucent white boldly veined with black. The underside is similar in the male but the female has brown veining. Moreover, the female loses most of her scales by rubbing her wings together, resulting almost-transparent. This butterfly can be distinguished from other members of white butterflies of the genus "Pieris" by its distinctive veined wings. The eggs are yellow at first, darkening with age. The caterpillars are greenish grey with transverse banding . The pupa is creamy white, marked with black, attached by a silken girdle to a twig. Biology. The flight period of the black-veined white is between April and July. The adults are quite social and their abundance varies greatly from year to year. The eggs are laid on the food plant, usually a member of the rose family Rosaceae and often on trees and bushes ("Malus domestica", "Malus micromalus", "Pyrus communis", "Pyrus serotina", "Sorbus intermedia", "Sorbus hybrida", "Sorbus aucuparia", "Crataegus monogyna", "Crataegus oxyacantha", "Crataegus jozana", "Prunus spinosa", "Prunus padus", "Prunus ssiori", "Betula" spp., "Salix phylicifolia", "Chaenomeles lagenaria"). The eggs  are laid in groups of 30 to 100. They take about three weeks to hatch. The caterpillars tend to remain in a group with a communal larval web. This species has one generation each year. The caterpillars overwinter communally in a webbing tent with entwined leaves. Caterpillars feed close together on the leaves of the food plant at first, before dispersing in the later developmental stages to other parts of the tree. The pupal stage lasts about three weeks.