Any chance of a species ID? - Macrosiagon flavipennis

Moved

… Aaron Schusteff, 7 April, 2014 - 12:56am

Probable Species ID

I'm pretty sure this is M. flavipennis. It keys clearly to that in Rivnay(1) and Linsley & MacSwain(2)...though perhaps there's a small (unlikely) possibility it could be M. fernaldum.

In particular, I think I can see a "posteriorly excavated semi-erect process" at the apical end of the pronotum, which is diagnostic of just those two species in Macrosiagon. Males of both species have yellow elytra, but Rivnay states here that: "The male of M. fernaldum has the abdomen red or brown red, wings hyaline; while M. flavipenne has a black abdomen and wings smoky at least near costal margin."

What I can see of the abdomen looks black rather than red or brown, which would point to flavipennis. Might you be able to post a profile showing more of the abdomen? That would help nail down the ID.

I'm somewhat hesitant about the wing color, as Rivnay's descriptions state that fernaldum has wings yellowish-hyaline (like in your image), whereas flavipennis has wings yellowish brown...but I guess the latter fits your specimen as well. And fernaldum is described as having "tibial spurs truncate, smooth at tip"...whereas your specimen seems to match better with "tibial spines acute" of flavipennis.

Finally, M. fernaldum is supposed to be restricted in range to southern California. Zack Falin's comment here indicates he doesn't think it would be found much further east than western Arizona...if even that far. So your New Mexico locale presumably excludes it.

We currently have only one male flavipennis post:

I think yours will be our second. Hopefully Zack Falin can give a look soon and confirm or correct my putative ID. Nice find!

… Aaron Schusteff, 14 December, 2013 - 5:28am

Sorry for the late reply,

but I must have unsubsribed and missed your post. Thanks for the information you provided Aaron, very good. I posted a profile image, the abdomen definitely looks all black to me - flavipennis?

… Mark S. Romero, 31 March, 2014 - 6:42pm

Great!

The additional profile shot verifies the abdomen is black. So, along with everything else, I think there's little doubt this is indeed M. flavipennis.

… Aaron Schusteff, 7 April, 2014 - 12:53am

ID confirmed by Zack Falin

"Yes, a male M. flavipennis. While M. dimidiata has a small 'cup-like' process at the base of the pronotum, M. flavipennis has a rather large (and odd!) notch. It is also true that M. flavipennis has a much more flattened, impressed frons (creating a relatively more narrow and "sharp" vertex) than M. dimidiata -- this doesn't show up well in the photos.
"The distributions of these 'species' is crazy: I collected a female M. flavipennis in Paraguay some years ago!"

… v belov, 15 April, 2014 - 9:30am

Thanks, =v=

Always good to get Zack's illuminating comments on these challenging taxa. I'm hoping he'll eventually get a chance to comment on my post below:

… Aaron Schusteff, 15 April, 2014 - 6:55pm

Moved

Moved from Wedge-shaped Beetles.

… v belov, 26 June, 2013 - 2:11pm