Singing the Blues

[Michael Klein]

I have attached a few dorsal and ventral of some males and females of an
Arrowhead Blue (Glaucopsyche piasus) and Boiduval's Blue (Plebejus
icariodes) located in San Diego County at a location called Guatay.  It is
within the foothills of the Cuyamaca Mountains at an elevation of
approximately 3,300 feet.  These were recorded on 5/18/03.

Hopefully this can be an instructional time for all of us as to how variable
just these 2 species can be based upon non-regional field guides.  As well
meaning as field guides are to be, (and I appreciate all of the more recent
ones) they sometimes do not capture all of the subtle variations local
regions can have.  Having experienced the southern Sierra's last year with
Ken Davenport, I can appreciate the overwhelming frustration he can
sometimes run into.

I was attempting to identify them to subspecies level when I stumbled into a
road block:

For Arrowhead Blue, I started with the Butterflies of Southern California by
Emmel and Emmel (even though some things are old, it is still a very good
reference).  I also used the Systematics of Western North American
Butterflies by Emmel.  Here is where I have stumbled - According to
Systematics a subspecies umbrosa has a type locality for San Diego County
near Big Laguna Lake in the Laguna Mountains approximately 20 miles away.
It states that the host plant is Lupinus formosus.  When you try to compare
the specimen to the book's photos (not the best) my Guatay speciman does not
match.  It actually resembles more to subspecies excubita but according to
Systematics this subspecies only gets as far south as the east slope of the
Sierra Nevada in Kern County and is closely associated with Lupinus
excubita.  Well where my specimens are located in Guatay, all that is there
is Lupinus excubita.  I even photographed eggs within the inflorescence of
the lupine.  So is it umbrosa where not host plant is found or is this
excubita or even a possible new undescribed subspecies?  One of the things
you might notice on the male and female dorsal hindwings are subtle orange
margins, which none of the field guides show for this species.

For Boiduval's Blue, I started with the SoCal book and in San Diego County I
have always believed our subspecies was evius.  But according to the SoCal
book its hostplant is Lupinus densiflorus var. glareosus.  Since this is an
older book I decided to look at Systematics.  Evius was not discussed but a
new subspecies - argusmontana was described but its range is Inyo County.
When I compare the photos to my specimens, they appear to be similar and
they had the same hostplant (Lupinus excubitus).  I have photographed a
mating pair on excubitus since that is the only lupine at this location.
So, Is it possible that the hostplant information for evius needs to be
updated or do we have another subspecies in San Diego County not previously
reported?

As I mentioned earlier, as much as I support and enjoy 'North American'
butterfly books or even Western U.S. books, regional or local guides may
still be the better resource to be able to capture the local variation.

I am hoping that some of the Southern California experts can input to this
email so that I can have a better understanding as well as instruction
others from around the country.

Michael Klein
San Diego

P.S. Sorry for posting the photos this way, I seem to have troubles still
getting things to work properly on Yahoo.
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