Australian painted lady similar to those in the late summer. Seasonal changes could trigger the development of spring and fall body forms that are ideal for the migration patterns described above. During periods of large migration in Australia, and with the possible help of strong winds, the Australian painted lady migrates across the sea to New Zealand. Multiple occurrences of this butterfly in New Zealand were reported in the 1960s. In the spring of 1968, they appeared on the western coast of New Zealand near the sea, and were unusually abundant. The species is unlikely to be established in New Zealand, as no
Australian painted lady to lowered temperatures. This demonstrates the phenotypic plasticity, or the tendency for visible traits to vary with changing environmental conditions, of the painted lady butterflies. It also suggests that the painted lady is the ancestral form, and environmental stress slowly drove speciation by adaptation into the Australian painted lady. In other words, the Australian painted lady most likely evolved from the painted lady due to the environmental conditions in Australia. The Australian painted lady's distribution is restricted to Australia. The closely related "V. cardui" is found throughout the rest of the world, so the two species have an allopatric distribution.