In Minnesota, 2011 certainly has been the Year of the Giant Swallowtail. As I recently blogged, this handsome butterfly usually does not range north of Iowa. This distribution is understandable, since the larvae require citrus trees. The adults, nevertheless, do occasionally migrate into the upper Midwest. Jeffrey Hahn, of the Minnesota Extesion Service, writes that Giant Swallowtails can not reproduce in the state because of our lack of citrus trees. The male Giant Swallowtail in the background of this photo was clearly more interested in this female than he was in the garden flowers. Perhaps he was interested in giving reproduction a try. But, because of the larvae's citrus requirements, I doubt that the reproductive cycle will be successful here in Minnesota. These Giant Swallowtails cavorted in our CSA (Community Sustainable Agriculture) farm in southern Dakota County.
Update: A reader writes that the Prickly Ash, a fairly widespread understory shrub/tree in Minnesota is listed as a host plant for Giant Swallowtail larvae. Thus the butterfly might propagate locally.