Painted Lady butterflies are the most wide-ranging species of butterfly in the world, leading some to call them cosmopolitan butterflies. While they inhabit five continents, they cannot live in Antarctica because of the cold temperatures, and they are unable to reach the island continent of Australia because of its isolation. Painted Ladies undergo yearly migrations, leaving their warm winter homes for their breeding grounds located in more temperate climates.
Once they arrive in their breeding grounds, Painted Lady butterfly males seek out territories that have plenty of host plants capable of feeding their offspring. When a female approaches, the male takes flight and attempts to mate with her. After successful mating, the female deposits the eggs on a host plant. The hatchling caterpillars begin feeding immediately until they grow large enough to pupate and turn into an adult butterfly. When a great number of caterpillars inhabit the same area, they often form silken webs. These webs are thought to provide the growing, and vulnerable, caterpillars with some protection from predators.
Although butterflies are usually thought of as gentle creatures, Painted Lady males defend their territories very aggressively from other males. While waiting on their chosen perches for a female to approach, they immediately attempt to drive off any intruding males.