by Ilse Gebhard, KAWO member
Our earliest entry for finding and identifying an American Painted Lady (Vanessa virginiensis) is in our first butterfly book, one of those Audubon Society Pocket Guides. This entry is not a happy one: “6/10/91, grill” — car grill, that is — but does remind us of the many ways our modern way of life endangers the other species on our planet.
The first entry for a caterpillar of this species is “front yard prairie, 8/26/99,”which in retrospect is BC, “before caterpillars” became one of my passions. Two years later, in mid-August, I came across three more of these caterpillars munching away at Sweet Everlasting (Pseudognaphalium obtusifolium) in the same front yard prairie. By this time, it was AC, “after caterpillars” had become one of my passions.
So, into the raising jars the inch-long caterpillars went. My supply of Sweet Everlasting, a preferred host plant, was limited to the one I had found them on. But not to worry. By the next day I had found several plants in the area of our property that had been oak savannah before settlement.
The caterpillars were beautifully marked with contrasting yellow-green stripes and dark red and white spots on black bands and were covered with many black, branched spines. They clearly were late instar larvae, since early instars are all black. After five days they attached themselves to the provided sticks and formed tan-brown mottled chrysalises. The chrysalis stage lasted nine days for one and ten days for the other two.
It always amazes me how different the upper and under sides of the wings of many butterfly species can look and this is certainly the case for the American Painted Lady. The upper sides are mostly orange with various black marks and a few white spots near the apex of the forewing. The underwings are tan and brown, with a pink spot in the forewing and a distinctive cobweb and eyespot pattern in the hindwing. It can easily be distinguished from the very similar looking Painted Lady because it has two large eyespots versus four small ones for the latter.
There are conflicting opinions on what happens to the adult American Painted Ladies in winter in northern states. One book says they are not likely to survive, another one says they hibernate successfully and a third states that they migrate south in the fall.
First flight dates for butterflies that are known to hibernate as adults in Michigan are Milbert’s Tortoise Shell (3/22), Mourning Cloak (3/21), and Comma (3/22). In contrast, the first flight date for the American Painted Lady is 4/30, a month later, and coincides more closely with those of its Vanessa relatives, the Red Admiral (4/23) and Painted Lady (5/16). The latter two are cold intolerant and overwinter in the far South and Southwest and re-colonize the northern regions each year as spring advances. The American Painted Lady likely follows the same pattern.
The re-colonization of the northern regions by Red Admirals and Painted Ladies is highly variable in numbers and dates and likely depends on weather. For example, 2001 was a very good year for Red Admirals in our area, starting in early spring, while I never did see one in 2002 and only a few in 2003. I did not record any Painted Ladies in 2003 until mid-September, when in a two-day period I recorded them for Kalamazoo, Barry, and Van Buren counties.
There is some data that indicates a southward migration of the Vanessa butterflies in fall. In the fall of 2003, there were a number of reports of Painted Ladies doing so, including ours. As my husband Russ and I were driving southwest through Illinois one day in late September, a number of them crossed in front of us going south. We reported them to the Red Admiral and Painted Lady Research Site.