I was told that is what the Butterfly was, and they look identical to me, they have the same markings, the same blue design with center red dot. Same body, the only difference I could see was the other one had longer wing tails, but I assumed that one was male and one was female.. So Sorry if I made a mistake, next time I will not trust the identity I was giving of a insect. It was a case of mistaken identity, I am sure alt of people would of thought they were the same.

Although many of our info pages are blank (we only have so many editors filling them in) always check the "Info" page for a species and see if there is anything on how to identify, and check to see if they have a range. 2-tailed is a western species.

Leave these here until we can get an ID.

What is this butterfly then?

The only black and yellow swallowtail butterfly in Massachusetts is the Eastern tiger swallowtail, Papilio glaucus. And the Canadian Tiger Swallowtail, P. canadensis, which I just remembered. But only those two are real possibilities.

It's a female - they have more blue on the hindwing. Males have only a bit of blue, if any.

Differences from Two-Tailed Tiger:

Only one row of black-encased yellow spots on the outer edges of forewings. (Two-Tailed has two rows, the inner one is smaller and more gray.)

Black "tiger stripes" on forewings are wider.

Hindwing has two distinct "tiger stripes," both appearing to connect to the inner stripe on the forewing. One extends to the bottom of the hindwing, the other extends only half. Two-Tailed has one stripe extending the entire length, but only a short "dash" beside it, which doesn't reach either the top or bottom of hindwing.

Only one "tail" on each hindwing. Two-Tailed has two, at least early in its adult life. All swallowtails may experience wing damage and tail loss from life's hardships, but fresh, colorful individuals like this usually have tails intact.

Location - all I know about the Two-Tailed is that it's the state butterfly of Arizona, but that instantly made me wonder about this Massachusetts butterfly!

Papilio glaucus (Eastern Tiger Swallowtail), but they all look so close we really need an expert to point out the subtle differences.

Massachusetts locale narrows it down an awful lot - P. glaucus and P. canadiensis are the only natives that look like this. is the only native one. Another black and yellow Papilio could show up if it were storm-blown, flew a very long way for some reason, or were released from captivity, but a wild one would show signs of wear and tear from the long trip/storm damage. We can't rule out an escaped captive but it just seems unlikely, native swallowtails aren't "exotic" enough for most butterfly houses.

I edited this to reflect having just thought of the Canadian Tiger, I don't know how to tell that from P. glaucus, I didn't mean to be misleading myself!

those are the two I got stuck on. Pretty sure it wasn't Appalachian (but not enough to bet money on my lack of skill in this area). But the other two are trickier.

I'm spoiled by living spang in the middle of the Mid-Atlantic, none of those Canadian species coming down, very few Southern species coming up, no Western species getting this far over - I have fewer swallowtail options to think about!

"inner margin of hindwing upperside" seems like a fairly narrow black stripe.

okay and thank you