Which creature is the most widespread of its kind, tries to stay in warmer climates, and has a name perfect for an artistic masterpiece?
Painted Lady Butterflies!
The cosmopolitan butterfly
Painted ladies are the most widespread butterfly species. Their range covers every continent except Antarctica and Australia. Painted Ladies tend to stay in warmer climates, although they may also migrate to colder climates in spring and fall. Their range and migration routes granted them the nickname of ‘cosmopolitan butterfly.’
Unlike many other migratory species, Painted Ladies don’t follow a seasonal migrational pattern. Scientists theorize that they migrate according to incoming extreme weather, such as heavy storms. These events determine the survival rate of plants that Painted Lady caterpillars depend on. Another theory is that migration patterns are related to overpopulation. In Mexico, when there are too many butterflies in one region, competition for nectar grows. Rather than fight over limited resources, some butterflies prefer to flee north to the United States.
Like Monarch butterflies, Painted Ladies migrate over the span of multiple generations. No one butterfly will make it from Mexico to Canada and back, but over the course of 6 generations the migration across North America is complete. Also like Monarchs, Painted Ladies tend to migrate northwest in the spring. On this route, Painted Ladies fly low to the ground – only about 6 to 12 feet above the earth. Although this makes them easy to find and identify, it puts them in danger of vehicle collisions. When migrating during autumn, they do the opposite – they fly so high that most people don’t even notice the vast journey happening above their heads.
Painted ladies are considered medium-sized butterflies. This extra wingspan (compared to their smaller-sized relatives) allows them to fly up to 100 miles per day during migrations, and they can fly up to 30 miles per hour! By covering so much ground in such a short period of time, Painted Ladies beat Monarchs in the race to the North (sorry, Monarchs – we still think you’re amazing). Thanks to a head start in spring traveling, Painted Ladies reach their destinations in time to feed on spring annuals such as fiddlenecks.
The thistle butterfly
Painted Ladies, like other butterflies, drink nectar from plants. They have four types of color receptors, giving them the ability to see colors and patterns that we can’t. Depending on what color a flower has, a butterfly will choose to land on it and taste it with receptors in their feet.
The favorite nectar of Painted Ladies is found in thistle plants – granting them their second nickname: ‘thistle butterfly.’ Painted lady caterpillars also feed on thistle plants, among other hostplants such as hollyhock, mallows, and asters. In total, caterpillars feed on over 300 hostplants. Some of these plants possess toxic compounds that the caterpillars store in their blood (or hemolymph), creating a defense mechanism against birds and other predators.
Another defense mechanism Painted Ladies have lies underneath their wings. On the outside of their wings, these butterflies sport bright colors to attract mates, but these colors make them easily visible to predators. To balance the burden their beautiful colors bring, Painted Ladies have more neutral colors on the underside of their wings that resemble camouflage.
Learn more about the lives of these cosmopolitan, thistle-loving butterflies:
I’ll flutter away now!
Tania
Tania graduated from Tufts University with a Master of Science in Animals and Public Policy. Her academic research projects focused on wildlife conservation efforts, and the impacts that human activities have on wild habitats. As a writer and activist, Tania emphasizes the connections between planet, human, and animal health. She loves hiking, snorkeling, and advocating for social justice.
Sources:
https://www.colorado.edu/cumuseum/2020/06/24/painted-lady-butterfly
https://www.thoughtco.com/facts-about-painted-lady-butterflies-1968172
https://www.amnh.org/learn-teach/curriculum-collections/young-naturalist-awards/winning-essays/2011/butterfly-buffet-the-feeding-preferences-of-painted-ladies