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V. R. BURKHARDT
yellow in the wet season, whilst in the dry the yellow is darker with numerous white and reddish-brown markings. The upperside of the male in the wet form has a broad black border to the hind wing, the dry form has none or very little rim. The upperside of the female varies much, but in the wet forms the ground colour is generally white, with a broad and suffused dark brown border to the hind wings; occasionally almost the whole upperside is dark brown, except the diagonal white marking across the fore wing and a slight whitish patch on the anterior margin of the hind wing towards the base. In the dry form the ground colour of the upperside inclines to yellow, and there is little, if any, dark border to the hind wings.
There are two "Whites" corresponding to their counterparts in England, Pieris rapae, and Pieris nerissa. The former is a recent introduction, not recorded till 1952 when it must have been introduced in the larval form in cargoes of Shantung cabbages from the north. In the wet season form the spots on the fore wing are deep black, whilst they are grey in the winter weather. The insect is practically identical with the Small Cabbage White in England and only differs in that the grey scaling at the base of the wings is more pronounced. As a sub-species of P. rapae it is named crucivora from its partiality to cabbages.
About ten years ago it swarmed in market gardens and practically displaced the indigenous Pieris canidia, which became very scarce. The use of insecticide spraying has, however, greatly reduced the numbers of both species.
Pieris nerissa, which corresponds to the Green-veined White in England, is most abundant in the months of June and July, when the wet season form exhibits the veining deeply marked with brown, and the anal margin of the hind wing is often suffused with yellow. The dry forms are much paler than the wet, both on the upper and undersides.
Certain of the Lycaenidae (the Blues) also show seasonal variation on the underside. Probably the commonest Zizeeria maha, which is ubiquitous and never rises above knee height, is chalky white in the wet season, with strongly marked black spotting. In the winter the underside is ochre, and the spots merely darker in shade than the ground colour. In Chilades laius the spotting is black in the wet season and coral pink in the dry.