28 June 2010
The American Lady butterfly (Vanessa virginiensis)
American Lady butterflies (Vanessa virginiensis) are not uncommon; the real challenge is to document an entire life cycle, starting with the egg. To do that, one has to locate one of the food plants for the caterpillars - Pussytoes, Pearly Everlasting, or Burdock. Here in Wisconsin there's lots of burdock, but in the early spring it's also easy to spot Pussytoes (Antennaria spp.) because they thrust their fuzzy cats-paw-like flowers above the other vegetation on long stems.
Finding the eggs is a challenge. The upright stems do have small clasping leaves, but the American Lady prefers to oviposit on the rosette of basal leaves next to the ground, and those leaves tend to be obscured by grasses and low vegetation.
Butterfly Garden forum at Gardenweb I've read reports of Ladies ovipositing on the flower stem or head, but have never seen a photo of such or found one myself; it would be a real challenge to locate an egg in that complex flower structure.
On closup view the egg looks like a little gooseberry -
these three posts at the GardenWeb Butterfly Garden Forum.
I have only a few photos of the caterpillars because as a whole I saw them very seldom. I eventually became suspicious about the lack of apparent activity and opened one of the nests…
The scene was replicated in a couple other nests, and a couple more were just empty, with no sign of the cat. I finally decided that some “skins” I had seen earlier and had assumed were shed during molting were probably desiccated bodies of parasitized cats.
Eventually two cats successfully formed their chrysalises on the tulle; I used a bit of dental floss to tie them to a stick for more stability:
The last chrysalis finally turned quite dark one evening. The next morning I moved it to my breakfast table and kept it by my side while I started the NYT Sunday crossword. I was planning to get some pix of the eclosion, but the process was of course silent and I was engrossed, so when I finished the puzzle and looked up, she already had her wings fully inflated -
These are common butterflies that range coast-to-coast and Canada-to-Mexico in the United States, and for that reason I suspect the delicate beauty of their wing patterns is not fully appreciated. Try supersizing the photos with a click...