The Eastern Tiger Swallowtail doesn't usually make it this far north in Vermont, unless the range has shifted in recent years. I think it would be a rare sighting in Vermont, worth reporting. My favourite way to tell the Eastern and Canadian apart is that, if it's in Canada, it's a Canadian Tiger Swallowtail! It works!
My Kaufman butterflies guide also tells me that, if you look under the forewing of the butterfly, the Canadian swallowtail has a continuous band of yellow along the back margin, with black stripes on either side, while the Eastern's is broken up and looks more like a series of yellow windows framed by black… it's tough to describe, but you can find it in a field guide! I guess the key is to watch long enough (or catch the butterfly in a net) so that you get a glimpse of the underwing.
Does anybody know of any butterfly counts going on in Vermont this spring or summer? They're a great way to get out and get to know butterflies!
