Diptera.info

Posted by John Carr on 03-01-2015 18:33

Florida, USA, December 12, 2014.

This was posted to BugGuide (http://bugguide.n...ew/1028035) and is reposted here with the photographer's permission.

The name Prosena siberita was suggested. That European species is introduced in America and was only known from northeast USA as of the 1965 catalog of Diptera. The photo is from southern Florida, a subtropical climate that could be considered a transition to the Neotropical region.

The arista is long haired, consistent with Dexiini.

I compared photos here and ended up confused. Is it a variable species (shape of calypters, acrostichals and marginals on tergites)?

Edited by John Carr on 24-01-2016 14:21

Posted by Zeegers on 04-01-2015 12:20

Dear John

You are right with Dexiini. It doesn't look like Prosena siberita to me.
You have your own longtongues in the new world: Mochlostoma if I remember correctly. I would try to look there.

Theo

Posted by John Carr on 04-01-2015 13:31

Zeegers wrote:
Dear John

You are right with Dexiini. It doesn't look like Prosena siberita to me.
You have your own longtongues in the new world: Mochlostoma if I remember correctly. I would try to look there.

Theo

Mochlostoma would be an etymologically justified but code-unjustified emendation of Mocholsoma B&B 1889.

The native American long-beaked Dexiini I know of are Prosenoides (with upcurved proboscis) and Mochlosoma. There is also Ptilodexia which is supposedly distinguished from Mochlosoma mainly by having proboscis shorter than head height.

Posted by John Carr on 24-01-2016 14:26

Norm Woodley said Prosenoides flavipes, which I had considered then rejected because the proboscis curved the wrong way. Several photos posted to BugGuide look just like another Prosenoides except for that detail. I now think that descriptions of proboscis shape are only valid for dried specimens, and live flies may bend differently.

Descriptions of long-beaked American Clausicella note variation in curvature.