Who is here? 1 guest(s)
 Large abdomen (with eggs perhaps?) and green halteres
|
|
| Stephen |
Posted on 30-08-2007 21:12
|
 Member Location: Posts: 1322 Joined: 12.04.05 |
Can someone provide an ID for this nice fly? Date: 13 July 2007 Location: Mountains, alongside a small river, West Virginia USA Edited by Stephen on 30-08-2007 21:37 --Stephen Stephen Cresswell www.americaninsects.net |
 |
|
| Stephen |
Posted on 30-08-2007 21:14
|
|
Member Location: Posts: 1322 Joined: 12.04.05 |
Here's a view of the front of the head.
--Stephen Stephen Cresswell www.americaninsects.net |
|
|
|
| Stephen |
Posted on 30-08-2007 21:17
|
|
Member Location: Posts: 1322 Joined: 12.04.05 |
Here's the third and final photo.
--Stephen Stephen Cresswell www.americaninsects.net |
|
|
|
| Sundew |
Posted on 31-08-2007 01:17
|
 Member Location: Posts: 3890 Joined: 28.07.07 |
This is a "pregnant" female, and if the photos were taken in Germany, I would suggest Melanostoma scalare - no idea whether you have the same species in West Virginia. For comparison, look at the pictures given in http://www.natur-...-262.html#. I hope my amateur opinion is not too far away from truth... Best wishes, Sundew |
|
|
|
| Susan R Walter |
Posted on 31-08-2007 08:47
|
 Member Location: Posts: 1794 Joined: 14.01.06 |
Definitely M scalare (unless you have some exact lookalike over there). I find only the females of scalare have those acid green halteres, but also the pattern of abdominal spots and facial dusting indicate scalare.
Susan |
|
|
|
| Stephen |
Posted on 31-08-2007 10:06
|
|
Member Location: Posts: 1322 Joined: 12.04.05 |
Sundew, Susan, thanks very much for your help with this one! Your ID sent me to the site www.nearctica.com, and it lists six Melanostoma spp. for the Nearctic, and they are: Melanostoma ambigua Fallen 1817 (Scaeva) Melanostoma angustatum Williston 1887 (Melanostoma) Melanostoma bicruciata Bigot 1884 (Melanostoma) Melanostoma dubia Zetterstedt 1838 (Scaeva) Melanostoma mellina Linnaeus 1758 (Musca) Melanostoma parva Williston 1882 (Cheilosia) At www.bugguide.net I found a similar gravid female photos identified by Gerard as Melanostoma mellina (acid green halteres too): http://bugguide.n...760/bgpage I don't know if mine is the same species as in the BugGuide photo. At any rate I am very glad to know the genus of this one. Thanks again, Sundew and Susan! Edited by Stephen on 31-08-2007 10:08 --Stephen Stephen Cresswell www.americaninsects.net |
|
|
|
| Susan R Walter |
Posted on 31-08-2007 12:33
|
|
Member Location: Posts: 1794 Joined: 14.01.06 |
Well, now I'm confused - I'll go off and look at some books. 
Susan |
|
|
|
| Stephen |
Posted on 31-08-2007 16:58
|
|
Member Location: Posts: 1322 Joined: 12.04.05 |
Another question I meant to ask before, what is that large round black structure below the antennae?
--Stephen Stephen Cresswell www.americaninsects.net |
|
|
|
| Sundew |
Posted on 31-08-2007 18:02
|
|
Member Location: Posts: 3890 Joined: 28.07.07 |
In the internet, there is a paper on syrphids by D. Miller (Transactions and Proceedings of the Royal Society of New Zealand, Vol. 53, 1921; http://rsnz.natli...03850.html), where the faces are described: Face of varying shape; concave, convex, arched, or vertical below antennae, with or without a central tubercle or swelling; sometimes produced at oral margin; clothed with hairs or bare, and sometimes transversely wrinkled; oral margin horizontal, descending or ascending... In a following key, you get to Melanostoma via face not vertical to oral margin but with a distinct knob in middle I could not find a more recent paper explaining the nature of this round knob - sorry! It's just there, fancy Melanostoma design...Sundew |
|
|
|
| Stephen |
Posted on 01-09-2007 13:22
|
|
Member Location: Posts: 1322 Joined: 12.04.05 |
Thanks for the info on that unusual facial structure. Maybe someday we will learn a function that it performs!
--Stephen Stephen Cresswell www.americaninsects.net |
|
|
|
| Juergen Peters |
Posted on 05-09-2007 01:56
|
 Member Location: Posts: 13502 Joined: 11.09.04 |
Hello! Up to this thread I never noticed green halteres in Melanostoma. Many of them around here (Ostwestfalen/Germany) at the moment, and I assumed them to be mostly M. mellinum. But yesterday I found this female - with light green halteres! 
Edited by Juergen Peters on 05-09-2007 18:01 Best regards, Jürgen -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Juergen Peters Borgholzhausen, Germany WWW: http://insektenfo... -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= |
|
|
|
| Jump to Forum: |
but don't see the image in the post.