tyche in North America ?

[Kenelm Philip]

	This is an interesting story--I believe I commented on it earlier,
but here goes again.

	In _The Butterflies of Canada_ by Layberry, Hall, and Lafontaine,
Booth's Sulphur is called _Colias tyche_ (de Boeber, 1812), rather than
it's traditional name: _Colias boothii_. _Colias thula_ is included as
well. In addition, although not mentioned in that book, the Fennoscandian
_Colias nastes werdandi_ is now assumed to belong with _tyche_ rather than
with _nastes_.

	At the end of the _tyche_ section in _The Butterflies of Canada_
is the following note: "Research on this species in Russia, where it also
occurs wiyt _hecal_ and _nastes_, further supports its status as a
separate species and has shown that the correct name for the species is
_tyche_ (Mikkola, in litt.)." So I sent Mikkola e-mail asking for a copy
of the paper he was presumably working on--and got a reply saying the
paper had never been written, because he was unable to come up with
a set of reliable characters for the new grouping.

	So the name in _The Butterflies of Canada_ is simply a conjecture.
A plausible conjecture, at least to some extent, but not backed up by a
taxonomic publication.

	Some background information: _thula_ was described as a ssp. of
_nastes_ (Hovanitz). I showed him a series of nastes from the TL for
_thula_--and he replied that nonetheless _thula_ was a ssp. of _nastes_(!)
So much for _that_...

	_C. thula_ appears to intergrade with _boothii_ as you go east.
Furthermore, there is an odd green _Colias_ in the western Canadian Arctic
Archipelgo which, as far as facies go, bears the same relationship to
_thula_ as _boothii_ from Baker Lake does to _boothii_ from the Boothia
Peninsula. Many years ago I decided that all these were _probably_ con-
specific across the North American arctic--and others have agreed.

	_C. "nastes" werdandi_ _looks_ like _thula_, not _nastes_. In a
book on Scandinivian butterflies I acquired a year ago, I read that
_werdandi_ emerges early in the summer, before _hecla_--which is exactly
what _thula_ and _boothii_ do--and prefers to fly in valleys--which again
is what _thula_ and _boothii_ do. _C. nastes_ prefers xeric habitats and
is often found on rocky ridges, and also flies (with _hecla_) later in the
summer.

	I know practically nothing about _tyche_, but it is plausible that
_werdandi_, _thula_, and _boothii_ are conspecific. Plausible is, however,
hardly a solid demonstration of that idea. People who wish to use the
names _thula_ and _boothii_ are certainly free to do so, until someone
comes out with a taxonomic papaer on this group.

							Ken Philip



 
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