Friday, June 16, 2006
Biodiversity Corner White Admiral
When and where seen: On June 8, Tom Brownrigg saw this butterfly fluttering around the entrance to his garage. He was able to photograph it when it landed in the driveway. It lives on the borders of deciduous forests where it finds birches, willows, poplars or other hardwoods on which to lay its eggs. Between now and the end of August you might see one around the garden or near the woods feeding on nectar, aphid honeydew, or on carrion.
Identification: Neither of the common names, White Admiral or Banded Purple, are aids to identification. The butterfly is not white, it doesn't command a fleet, and it isn't purple, but it is banded. The wings are jet black on the upper side with a broad white band across the middle and usually some blue or blue-green towards the edge of the hind wings. This one had two rows of blue markings between the white band and the edge of the wing. Sometimes, not on this one and more often in the western U.S., there are brick-red spots between the white and the blue. The underside of the wings also has the white band, blue and red spots where the wing joins the body, and a row of red spots near the wing edge. It is fairly large — about three inches across. Tom said it is a very striking butterfly and one you will remember having once seen it. All adult admirals are recognizable in flight by the way they alternate between flapping and gliding, and their habit of darting at other insect-intruders in their space.
Life cycle: The White Admiral spends the winter in either its caterpillar or chrysalis phase. The caterpillar is lumpy, bumpy, olive green and brownish with a white blotch in the middle. It looks like a blob of bird droppings which is its strategy for avoiding predators. The chrysalis uses the same disguise. I have taken to looking more closely at bird droppings and was surprised on Sunday by a bird splat on a leaf in Great Brook Farm State Park that turned out to be a moth.
References: Audubon Society Field Guide to North American Butterflies, Robert Michael Pyle; Peterson First Guides, Caterpillars, Amy Bartlett Wright.
Submissions for the Biodiversity Corner are encouraged from everyone. The only requirements are that the topic exists in the wild and was seen in Carlisle. Send a photo and some field notes to email@example.com.
© 2006 The Carlisle Mosquito