Catopsilia pomona, the common emigrant or lemon emigrant, is a medium-sized pierid butterfly found in Asia, Cambodia 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. Description 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. Male 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 almost reaches the tornus, in others terminates above vein 4; occasionally it is continued posteriorly by a series of block dots at the apices of the veins. Hind wing: generally uniform, unmarked, some specimens bear minute black dots at the apices of the veins. "On the underside the groundcolour is very variable, with white with a slight to strong ochraceous tinge, greenish white or sulphur-yellow. The fore wing is typically without markings, in some specimens with a patch of sulphur-yellow on either side of base of median nervure, in the very yellow examples the tornal area is often widely greenish white, in others (Catopsilia catilla, Cramer) it bears a spot variable in size on the discocellulars. This spot has a pearly centre and an outer reddish line. Many specimens have an irregular angulated narrow discal reddish line (the colour varies in intensity) that runs from the costa obliquely outwards to vein 7, and then obliquely inwards to vein 2, though this line is often absent in specimens that bear the discocellular spot; apex and termen sometimes very narrowly reddish. The hind wing is typically uniform, without markings; in var. catilla there is a single small spot at the end of the cell similar to that on