Yes, apparently in some areas the leg III ornamentation is nearly identical (likely due to hybridization), however, there are populations of clypeatus that have a more distinct leg III, where the top of the femur is bare, reddish, and swollen. There is also apparently hybridization between clypeatus and formosus, so we may have the same problem there. It's possible these are really subspecies of a single species rather than true species in their own right, but there just isn't enough data to make such a determination at present.

David Beaudette has some photos of clypeatus. I misidentified one in March as dossenus. He has better photos of a different individual on his Flickr (1, 2). These ones show a reddish distal third femur and blackish first femur and look pretty distinct. Jillian Cowles also has a photo of clypeatus on her website. She's going to try and post it on BugGuide in the near future.

Yes, David's specimens do look more distinct. For the ones that aren't so distinct, I think we'll just have to go by the white line above the anterior eyes, although apparently this is not 100% consistent either.

Hmm, you may be right.

These macros are very detailed at full resolution. Do you have any others? Maybe we could ask Marshall Hedin to take a look at some point.

I sent the photos to Wayne Maddison and Marshall Hedin. Dr. Maddison says he thinks it might be a hybrid.

Did he mention why he thought it was a hybrid? I suppose we could make a No Taxon category.

He was thinking it might be a hybrid due to the specific location (that dossenus is not previously known from) and the ornamentation of the 3rd legs. I sent him some more detailed photos, and now he is leaning towards it actually being H. dossenus: "Actually, these look more and more like pretty straightforward dossenus to me. The problem is that the westernmost dossenus aren't very distinct from clypeatus in third leg there. The further east you get, the easier they are to tell."

That's very interesting. Are there also differences in the first leg ornamentation? Do you think we should we move it to dossenus?

Yes, I believe dossenus has more greenish forelegs while in clypeatus they are darker (nearly black). This one is about midway, so hard to tell. Also, the ventral surface of the first tibia (not visible) is bare in dossenus, but clothed in whitish scales in clypeatus (at least typically). Considering how similar this specimen is to our existing dossenus photos, I would say go ahead and put it in dossenus.

I will keep this No Taxon category, just in case we get more putative hybrids. BTW-do you have a copy of Griswold?

Yes, I have a copy of Griswold, but all it has is one black and white drawing of the clypeatus 3rd leg and no illustrations for male dossenus. The 3rd leg descriptions are rather ambiguous. Maddison mentions in his 2003 Habronattus paper that the 3rd legs are similar between clypeatus and dossenus, but doesn't describe the differences.

Here's another update from Dr. Maddison: "Looking at my old picture, the third leg of the one in question looks like dossenus. Note that dossenus and clypeatus are very distinct in the Chiricahua area. Clypeatus has a slightly different morph west of the Chiricahuas that is more of a desert dweller (in the Chiricahuas it's woodland)."

This specimen is from the Santa Rita Mountains which are south of Tuscon, i.e. west of Chiricahua.