About the Lemon Migrant
Catopsilia pomona, the common emigrant or lemon emigrant, is a medium-sized pierid butterfly found in Asia and parts of Australia. The species gets its name from its habit of migration. Some early authors considered them as two distinct species Catopsilia crocale and Catopsilia pomona.
The species has pale and dark morphs in Australia. The form crocale has the antennae black and the form pomona has the antennae pinkish or red. The development of these forms has been linked to photoperiod and temperature during growth.
Quoted from Bingham, C. T. (1907) The Fauna of British India, Including Ceylon and Burma: Butterflies volume 2. "The upperside of the male is chalky-white, sometimes with a more or less broad and clearly defined basal sulphur-yellow area on both fore and hind wings; this sulphur-yellow colour is at times diffused over the whole surface of the wings, though generally it becomes paler towards the terminal margins. For the fore wing, the whole, or sometimes only the apical half, of the costa narrowly black, this color widened out irregularly at the apex; termen widely black at the apex, the colour narrowed posteriorly. This border in some specimens... Wikipedia →