I am submitting a number of swallowtail sightings from last July in an effort to better understand how to disentangle Canadian Tiger Swallowtails from Eastern Tiger Swallowtails. I had been using your guidance from last year based on (1) the time of the observation (i.e., if the milkweed is in bloom, then probably Eastern), (2) size (big = Eastern), and (3) whether the junction of the two black lines forms a wide letter U (if so, then Eastern). However, I am getting some confusing advice from the folks at iNaturalist. The relevant exchange, with some references to swallowtail samples from Massachusetts, is here https://www.inaturalist.org/observations/36124464 and here https://www.inaturalist.org/observations/36103604 Can you take a look at these July swallowtail sightings and let me know what you think? I am not qualified to be part of this discussion, but I see a lot of swallowtails flying in the Adirondacks in July, and I sure would like to know what they are.
Eastern Tiger Swallowtail?