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.
Found this pretty butterlies puddling in mud near the Thenmala dam. "Mud-puddling, or simply puddling, is behaviour most conspicuous in butterflies, but occurs in other animals as well, mainly insects; they seek out certain moist substances such as rotting plant matter, mud and carrion and they suck up the fluid. Where the conditions are suitable conspicuous insects such as butterflies commonly form aggregations on wet soil, dung or carrion. From the fluids they obtain nutrients such as salts and amino acids that play various roles in their physiology, ethology and ecology. This behaviour also has been seen in some other insects, notably the leafhoppers, e.g. the potato leafhopper, Empoasca fabae."