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.
The eggs of the butterfly are laid on various species of plants including several Cassias. Other host plants include Butea monosperma, Cassia fistula, Bauhinia species, Pterocarpus indicus, Senna alata and Sesbania species. The eggs are usually laid singly on the underside, at the margin of the leaves. Each egg is white, bottle shaped, and ribbed vertically. The eggs hatch in 3–4 days.