Polybiomyia - Polybiomyia bellardii

This specimen and all the oth

This specimen and all the other Polybiomyia bellardii on BugGuide have the scutellum more extensively yellow than all the Bold Systems pictures which are all from Central America. I think all records of pedicellata in U.S.A. will be mis-identifications, that is assuming pedicellata is a valid species, which I think it is.
All bellardia on BugGuide have the hind femora reddish or this one reddish on apical third and looking at the right hind leg femur on the posterior surface, even more than apical third reddish whilst all the Bold pictures have the femora totally black....

… Bill Dean, 1 July, 2019 - 3:55pm

Polybiomyia pedicellata?

This is indeed very similar to P. bellardii (i.e. entirely dark pleura; dark stripe across yellow scutellum; no supra-alar stripes; etc.)...but I was convinced when studying the associated iNat post last night that it's Polybiomyia pedicellata.

Keys to P. pedicellata in Shannon(1925) and also in Curran(1924)...though I now recognize more clearly that since Curran's treatment does not include bellardii, it's less compelling here.

The post is also in good agreement with the descriptions of P. pedicellata in Williston(1887) and Curran(1924)...but also with original description of P. bellardii in Shannon(1925). Distinctions in terminal couplet of Shannon's key boil down to legs more blackish or reddish and...most importantly...the degree to which the abdomen is pedicellate. Seems Shannon attempted to quantify/clarify "pedicellicity" using relative length-to-width of third segment...but nuances in the shape of the 2nd segment seem most critical to me. The abdomen here appeared sufficiently pedicellate to me last night...but now I'm wondering? [Compare w/ the iNat posts from Yucatán here and here...which also have more clearly black legs. And with the P. pedicellata images from BOLD...see links at bottom of info page.]

P. pedicellata is presumably rare in the US...more common from Mexico and into Costa Rica. But Stone et al(1) gave US range as TX, AZ, FLA.

I made a pretty thorough guide page for P. pedicellata this morning (perhaps somewhat in vain? ;-) before I saw this had been placed here as P. bellardii.

Let's think about this one a bit more. [For instance, consider Curran's Fig. 5 here...perhaps facial markings can help separate these two species? ]

… Aaron Schusteff, 1 July, 2019 - 2:34pm

I think it might be possible

I think it might be possible to interpret the key in Shannon(1925) to key this to P. bellardii -- I would want to see a specimen / photo of P. pedicellata, because T3 seems wider, and the legs more reddish, compared to the extent that these traits could perhaps reach in P. pedicellata (e.g. http://beta.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=478324).

… Even Dankowicz, 24 June, 2020 - 12:08pm

I am not very familiar with b

I am not very familiar with bellardii or pedicellata, but from what I read is that pedicellata has the fore and mid femora brownish to black, while they are reddish in bellardi, and pedicellata is more Mexico and an unconfirmed record in AZ, while bellardi is found in TX... But they are both very rare and I would not be surprised if they turn out as the same species.... so this might not be the final ID!

… Martin Hauser, 1 July, 2019 - 3:40pm

Moved

Moved from Polybiomyia.

… Martin Hauser, 1 July, 2019 - 9:58am

Looks like Polybiomyia bellardii

Looks like Polybiomyia bellardii.
I have sent it to Dr. Martin Hauser.

… Bill Dean, 1 July, 2019 - 2:45am