Eastern/Canadian Tiger Swallowtails

[John V. Calhoun]

Pavulaan at aol.com wrote:
> 
> The southern end of the glaucus cline is in Florida, where they achieve their largest size, and the black form is rare.  

As an aside, the black form of glaucus is actually not as rare in 
Florida as the literature has regularly suggested.  I often see the 
dark form more often during the season than the yellow form. In fact, 
there is some evidence that the dark form is becoming more common over 
time--a interesting and inexplicable phenomenon...       



>One quick look at Miller and Brown's
> Catalogue/Checklist of the Butterflies of America North of Mexico will show
> precisely how many names were devised for various butterflies.
>  Interestingly, many of these were found to be mere forms or varieties of
> butterflies.  Some forms or varieties turned out to be full species.


As Harry is well aware, a couple of excellent examples are Celastrina 
nigra (ebenina) and C. neglectamajor.  Both were thought to merely 
represent curious forms of the widespread C. ladon (or what was 
considered to be ladon/argiolus at the time...). Only relatively 
recently have these species been recognized as distinct.  One of the key 
factors in their discovery was hostplant utilization. Additional 
Celastrina are being revealed by both genetic and life history 
studies...Harry can certainly back this one up. 

Best,
John