Bombus ashtoni vs Bombus bohemicus in North America
With a recent discussion on an observation seen here regarding whether B. ashtoni is merged or not with B. bohemicus, I wanted to collate my thoughts in a google document on the matter for future reference.
For a TL;DR, I think that merging these two is premature at this time, and many authors saying they are merged are misquoting sources and referencing a field guide that gives no references or methods to back up the claim.
Edit: I had quite a bit of weigh in on this (surprising as I usually don't on journal posts) including Dr. Paul Williams (towards the bottom). To get both sides of the issue, I would recommend that anyone reading this article also read the comments, in particular Dr. Williams'. I still have the same opinion that I had before (that the current published data does not support synonymy), but the added details were enlightening and that would be a good way to see both sides.
Bombus ashtoni and Why It's Not Merged with Bombus bohemicus (yet)