Hirticollis or Rhodensis?

"The real purpose of the scientific method is to make sure nature hasn’t misled you into thinking you know something you actually don’t know."

― Robert M. Pirsig
This is the Hairy-necked Tiger Beetle Cicindela hirticollis. The only location I have ever observed this species is along the Wisconsin River by Sauk City. As my tiger beetle season typically goes, I consider myself extremely fortunate if I see only a single individual — they are not common. 
It's been my understanding that there are two forms of this tiger beetle in Wisconsin. There's the nominate form Cicindela hirticollis hirticollis and an even rarer form called Cicindela hirticollis rhodensis. According to the Wisconsin DNR page on the latter beetle, it's distribution is restricted to a few counties along the Great Lakes:

C. h. rhodensis is described as having reduced maculations (markings), so imagine my astonishment when I found this individual at the Sauk City Canoe Launch back in the summer of 2017:
As the crow flies, this location is less than 100 miles away from the nearest range of C. h. rhodensis in the map shown above. What's more, this particular subspecies has a Wisconsin State status of Endangered (END). Wow, I thought. I found a veritable endangered critter practically in my backyard. I was so thrilled that I reached out to several people who might be interested in knowing this discovery, but my bubble was quickly burst when I heard back from one of them:

"Our intent in listing this subspecies was to protect the Lake Michigan and Superior populations which have reduced maculations, although they vary and you can find well marked individuals, especially along western L. Superior. The inland populations should be referred to as Cicindela hirticollis hirticollis."

So my beetle was not the endangered form, just a poorly marked nominate form. Big deal, right? I still find it interesting to find variability even within a nominate form or subspecies. Naturally, I accepted the explanation from the experts and moved on with life. 
Recently, though, I got to thinking about this again when someone posted about finding a C. h. rhodensis in Northern Wisconsin in my Tiger Beetle Facebook group. Rekindled curiosity, I decided to dig a little deeper. Turns out, I discovered the following paragraph in my Pearson Tiger Beetle Field Guide:

"A continent-wide study of Hairy-necked Tiger Beetle mitochondrial DNA did not strongly support the validity of any of the named subspecies; however, western populations of the species did exhibit some genetic differentiation. Though the status of most or all of these subspecies is questionable, we include the names of previously recognized subspecies here pending further studies."

The two beetles in Wisconsin are not genetically distinct and intergrade considerably. 

And this:

"Subspecies C. hirticollis rhodensis is confined to the Great Lakes basin, and in Wisconsin it occurs along Lake Michigan and Lake Superior. Very few populations remain on the western shoreline of Lake Michigan. This form has in recent years become hard to find in Wisconsin and may need protection, since it only seems to occur on the few beachlines that are not heavily disturbed."

Here's a map of the Great Lakes basin, large red dot placed at Sauk City:
So why couldn't it be C. h. rhodensis?

Take a look at this one — same Sauk City Canoe Launch location:


Are you thinking what I'm thinking? Yeah, I think there's variability in the nominate form and the endangered subspecies is this same species — Cicindela hirticollis rhodensis does not exist. 

Cicindela hirticollis images © 2021 Mike McDowell