Here is a side by side using same year specimens:

https://flic.kr/p/26wWTgv

Here is an old faded pair of nelsoni:

https://flic.kr/p/26cuLMa

I don't have a graphic of old faded occidentalis to compare but the spring brood

of occidentalis looks more like nelsoni - but still different:

https://flic.kr/p/Teg8b5

So far the farthest south nelsoni I have seen (and recognized) are from Pink Mtn

https://inaturalist.ca/observations/150890821

https://inaturalist.ca/observations/150890760

On Sun, Mar 12, 2023 at 2:02 PM <tlpyle@...> wrote:

Norbert,

How do they differ?

Thanks. Bob P.

 

On 2023-03-12 10:00 am, Norbert Kondla wrote:

Maybe occidentalis and nelsoni are conspecific. Maybe they are not conspecific. It is an open question for me. Here is link to a distribution map that I have found interesting since it was published in 2001: https://flic.kr/p/2omG89v

Note the clean distribution gap between occidentalis and nelsoni in NE British Columbia. I wonder if it is real or if it is just a product of insufficient collecting to determine the facts on the ground. I suspect the latter. I also wonder if there are records of nelsoni further south in the Rocky Mtns than shown on this map and they have been so far misidentified as occidentalis.

I confess that I have not yet taken the time to review my own collections from that region to see if I have some nelsoni from further south.

I would like to chat with anyone who has specimens that might help to clarify this situation.

 

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Norbert Kondla

Calgary, Alberta, Canada  (elevation 1060 metres asl)

https://www.flickr.com/photos/118126948@N03/

 

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Norbert Kondla

Calgary, Alberta, Canada  (elevation 1060 metres asl)

https://www.flickr.com/photos/118126948@N03/