18 May 2014
Olympia Marble (Euchloe olympia)
I have been chasing this butterfly for about five years. Yesterday I finally managed to capture one on film.
The Olympia Marble is not rare or endangered; it is found across the United States in scattered environments suitable for its host plants (rock cress), and it is more secure in Wisconsin than in any other state. But it can be difficult to photograph. It is univoltine (one generation a year), with a flight period restricted to a month or two in the spring. It spends the rest of the summer in the larval stage, then pupates into a chrysalis for the fall and winter, rendering it susceptible to prescribed burns.
For years I have driven a couple hours north of Madison to participate in the early-spring field trip by members of the Southern Wisconsin Butterfly Association to the Bauer-Brockway Barrens State Natural Area to view the sometimes-abundant Olympia Marbles and a variety of elfins and Karner Blues. Yesterday morning I tracked several dozen Marbles but was - as in previous years - repeatedly frustrated by my inability to get close enough to this butterfly. In the field, on the wing, the Olympia Marble looks like an all-white butterfly, a vigorous flyer that nectars only briefly. When it settles, the topside spots (and the wing shape) distinguish it from the common Cabbage White. But you need to get up close and personal to appreciate the real beauty of this creature on the underside of the forewing, where there is a delicate green marbling pattern.
Yesterday, after two hours of walking through the jack pine woods and sand prairies, I found the fellow at top, who responded to my request that he hold still while I got down on my belly and crept toward him. With the lens about six inches away from the rock cress blossom that was blowing around on a windy day, I fired off 25-30 pix before I finally got the autofocus to center of the marble's wings rather than the background vegetation.
One more item from my bucket list finished.