Thread subject: Diptera.info :: Eumerus sp.

Posted by blowave on 29-11-2009 03:02
#1

Hello :)

I have three different lots of Eumerus sp. Two look the same species, Eumerus funeralis is the most common here.

The other one I only have one pic of but wondered if it might be Eumerus strigatus, a reasonably common one near my region.

The only other species here are E. sabulonum which is very unlikely, and E. ornatus which is a slight possibilty but pics I have found don't like like either.

I realise these can be difficult but with only two real possibilites I live in hope ;)

Janet :)

5 pics, fly 1: pic 1 taken on 3rd August near Lincoln UK

Edited by blowave on 29-11-2009 03:08

Posted by blowave on 29-11-2009 03:02
#2

fly 1: pic 2

Posted by blowave on 29-11-2009 03:03
#3

fly 2: pic 1 taken on 8th August

Edited by blowave on 29-11-2009 03:03

Posted by blowave on 29-11-2009 03:04
#4

fly 2: pic 2

Posted by blowave on 29-11-2009 03:05
#5

fly 3 taken on 29th May

Posted by blowave on 30-11-2009 03:21
#6

I found a key for Eumerus (and some other syrphid keys!). I have tried to key out the last pic, fly 3. It seems to only fit one of each option and the conclusions I have come to is Eumerus amoenus. We are not supposed to have that here so what have I done wrong?;)

I found a pic which looks very much like it....but that may be misleading.

http://www.biolib...e/id40089/

The key....

http://web.archiv...tml#item21

I start with 1b...go to 14

From 14a (14b is impossible) ... go to 15

15a > 17 (tergite 4 black with white dust stripes )

17b > 21 is the only one which fits

21a fits the ocelli which gives Eumerus ornatus.:|

Posted by blowave on 30-11-2009 04:31
#7

I just noticed the 'jizz' note at the side of 21a,

Jizz: elongate Eumerus with large eyes, frons very small. Note: If hypopygium white haired: E. strigatus


E. strigatus is the one I had thought fly 3 was! I'm not sure what the hypopygium is though.

Posted by blowave on 30-11-2009 04:42
#8

OK I now know what the hypopygium is but can't see it. That doesn't matter as we don't have the other species in the UK.:D

Posted by Andre on 02-12-2009 13:44
#9

Hypopigium is part of the male genitalia. Which you can't see here, for one thing because it's a female :)
Female Eumerus from species with these greyish stripes over the abdomen are very hard to impossible to identify, especially from a picture. That's why nobody is responding ;)

Posted by blowave on 02-12-2009 16:04
#10

Lol, nice to know it's a female Andre.:) The distance between the eyes might be the clue there, but flies can be confusing sometimes. Now at least I know it's only the males which have a hypopygium!:P

I now see there are three possibilities for here, strigatus, funeralis and ornatus, and as the key description for the ocelli seems to fit the last fly it should not be so difficult? I haven't yet got around to trying to key the other two I had but it looks very different so should be the other likely species we have. E. sabulonum is very rare and so far only 8 records on the west coast since 2000.

Oops, somehow I got the two in 21 muddled, must have been too late. ;) This is what I thought matched my last fly, which is 21b and should have been Eumerus amoenus which isn't here, but I don't think the 'jizz' note appied to 21b or does it?

Ocelli located on the middle of the vertex, distance between front ocellus and both hind ocelli equal to or somewhat longer than the distance between hind ocelli and hind margin of the eyes;

Back to square one :o

Posted by Andre on 02-12-2009 22:04
#11

No, it's not ornatus. Looking at pic one and judging the shape of femur 3, I would say strigatus.

Posted by blowave on 02-12-2009 22:30
#12

Thanks Andre. :)

I think the last fly is a different one, any ideas for that one? My head is swimming but I'm slowly getting better;).

Posted by Andre on 03-12-2009 21:13
#13

Same for the last one..
PS: I already was wondering why the background of that picture was different. Please try to prevent to put multiple species in one thread....

Posted by blowave on 04-12-2009 01:31
#14

Thanks again Andre!

But if you say they are the same, I haven't posted multiple species;):D

Posted by Andre on 04-12-2009 13:32
#15

Specimens then... :P