I too have both. P. thoas came papered with the name or if I caught it it was based on geography .and I followed .
This once again brings up the point of genetic analysis . It is quite limited. but comparing chromosome counts in ( fresh ?) male testicles certainly would be the definitive. What a great project for a PhD paper.
Look at the "Location " map and you will notice the dot's in the western end of Lake Erie. I have specimens that I collected on "Put-in-Bay" in the early 1960's. It has been established on these Islands for over 65 years that I am aware of. I was told that Cresphontes also occurs on Kelly's Island and Point Pelee in Canada. Can anyone in Canada or who has encountered it in Canada can confirm?
Yes Leroy , P.cresphontes is now quite common in Southern Ontario. I even saw them 200 km east of Toronto, Ontario.
In August till mid September it can be easily find in around woodlands sometimes flying together with second generation of P.glaucus. My first specimen I have collected was in mid 90s and it was as far North as Midland area at the Georgian Bay southeast shores. I don’t have it anymore as it was quite bid up specimen.