Pennsylvania’s other migrating butterfly — the painted lady
If you have been afield during the last month, hunting doves, fishing, scouting or just taking a walk, you have surely noticed the large number of butterflies. They are usually feeding on asters and goldenrods.
Locally, it seems to be a good year for the large orange-colored monarch butterflies. Their caterpillars depend on milkweed and just about everyone knows that they migrate into Pennsylvania and farther north during the summer months. In October, the last generation of adults flies southwest – all the way to Mexico.
Many other species of butterflies are about – buckeyes, sulphurs, and fritillaries, to name a few. However, most species don’t migrate like the monarchs do.
While monarch butterflies get most of the attention, this summer, much of the United States and southern Canada was overwhelmed with another migrating butterfly – the painted lady.
Painted ladies cannot handle the cold winters of the north, but each spring, adult painted ladies begin to migrate northward from Mexico to colonize much of the continent.
All summer, they are butterflies on the move – that is, always moving northward. Some years they make it to Pennsylvania, sometimes not, or they arrive only in small numbers.
Painted ladies are the most widespread butterfly in the world. They can be found on all continents except Antarctica.
Painted ladies have a wingspan of 2 to 2.5 inches and their wings are predominantly a pinkish-orange – accented with brown, black and white.
If you Google “painted lady butterflies” you will discover that there are many more in the United States than usual. Reports from Vermont, South Dakota, Colorado, Kansas, North Dakota and even southern Quebec document an unprecedented number of painted ladies this year. Much of Pennsylvania also has record numbers.
Many summers, I am hard-pressed to find painted ladies in central Pennsylvania – not this year. I have never observed so many. Huntingdon, Cumberland, Centre, Blair, Cambria and other counties – everywhere I go I see them.
Adult butterflies feed on the nectar of flowers. Painted lady caterpillars primarily feed on thistle leaves. Sometimes they are even referred to as “thistle butterflies. However, they also feed on soybeans. The high numbers of painted ladies this year prompted the University of Nebraska Institute of Agriculture and Natural Sciences to issue an alert in August to the state’s farmers.
While the painted lady’s spring migration is fairly well documented, their southern migration is not. An effort is underway to track this migration. A citizen-science effort, organized by the Montreal Insectarium, is collecting data. Visit www.eButerfly.org to learn more.
The pretty painted ladies will be gone soon, maybe to return next summer, or maybe not. Enjoy them while you can.