Australian Painted Lady...

Vanessa kershawi, commonly known as the Australian Painted Lady, is a butterfly that is mostly confined to Australia, although westerly winds have dispersed it to islands east of Australia, including New Zealand. During spring adult butterflies migrate south in large numbers from northern states of Queensland and New South Wales. In 1889, this migration was so large that trains were unable to generate sufficient traction because of the large numbers of butterflies resting on the tracks.