||The 2002 (M) images were taken during the period of April 2nd to May 7th @ H. The melanic image is the "swettaria" form The 2003 (M) image was taken during the period of August 21st to September 3rd. The 2004 (M) images were taken May 6th.
Judith Hooper wrote an interesting book, "Of Moths and Men", about H.B.D. Kettlewell's effort to prove Darwin's theory. Larva feed on alders, birches, blueberries, elms, hackberries, larch, pecan, Prunus species, walnut, willows and other trees and shrubs.