P. glaucus and P. canadensis

[Kondla, Norbert FOR:EX]

Re. the question about P. machaon and P. brevicauda. Yes, apparently some
people think that these are the same species.  What little I know about this
one is that the rational for this interpretation is the level of chemical
similarity in the gene segments that have been sequenced to date. Other
people of course hold a different view. To me they are such grossly
different looking insects that I see absolutely no reason to treat them as
one species.  Using chemical similarity to lump these species is akin to
using genitalic similarity to to lump different species (eg. boloria
distincta and B. astarte). I would want to see evidence of a fairly broad
zone of character intergradation between machaon and brevicauda before
viewing same species status as a reasonable interpretation. Interestingly,
another researcher has published his reasons for the interpretation that we
do not even have P. machaon in North America. A structural difference in the
egg micropyle was one of the criteria for that interpretation.  There are no
simple answers to these kind of taxonomic issues of what is a subspecies
versus a species. different people have different definitions and criteria.
different people will interpret the same data in different ways.  One can
chose to simple accept the latest published rationale for a particular
interpretation or one can chose to examine the available evidence and form
ones own interpretation. I use the latter approach as much as possible - but
it is time consuming to use this approach.

-----Original Message-----
From: gwang [mailto:gwang at mb.sympatico.ca]
Sent: Tuesday, June 05, 2001 3:26 PM
To: leps-l at lists.yale.edu
Subject: P. glaucus and P. canadensis


Hi y'all

I was under the impression that a sure way to distinguish P. glaucus and
canadensis was that the yellow marginal spots on the underside of the
forwings of canadensis were fused into a continuous band while the same
spots on glaucus were just spots and not a continuous band.  However,
under the species descriptions section at the Butterflies and Skippers
of North America website by P. Opler et al
(http://www.nearctica.com/butter/index.htm), they claim that the
continuous banding can be found in both species.  Any thoughts?  Any
other suggestions on distinguishing the two other than locality..etc?

Peace,
Xi

P.S.  They also claim that P. machaon now includes brevicauda.  How and
when did this happen?

 
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