Thread subject: Diptera.info :: Chrysotoxum (Syrphidae)

Posted by Rui Andrade on 27-09-2007 12:35
#1
Are these two of the same species?
Thank you

location: Oporto, Portugal
date: 2007/09/26

img408.imageshack.us/img408/1369/chrysotoxum1lo0.jpg

img408.imageshack.us/img408/9513/chrysotoxum2al4.jpg
Edited by Rui Andrade on 05-11-2007 19:05

Posted by jorgemotalmeida on 27-09-2007 12:48
#2
Another good one for Mimicry diptera! Smile

Posted by jorgemotalmeida on 27-09-2007 13:10
#3
Syrphidae... both... different species.

Posted by jorgemotalmeida on 27-09-2007 13:27
#4
Both are Chrysotoxum.

Posted by Rui Andrade on 27-09-2007 13:53
#5
Thank you, Jorge

stratiomyidlike syrphidsGrin......at least for meFrown

Posted by Andre on 27-09-2007 16:29
#6
Hi Rui!
The top picture looks like Chr. festivum. The second like a Chr. intermedium. Please collect them next time you see them (and any other Syrphids too Smile ).

Posted by Rui Andrade on 27-09-2007 21:01
#7
Thank you, Andre Smile

Actually, I collected the two specimens. I just put them in alcohol, but one of them had been dead for more or less 24 hours and I'm not sure if it was too long without it being in alcohol.

Just one question: are there any problems in putting more than one insect in the same jar?

Posted by Tony Irwin on 28-09-2007 18:27
#8
No problems, if they're from the same locality on the same date! Wink
Just occasionally, filling a jar with flies will dilute the alcohol so much that they are not properly preserved. Sad This is only likely to happen if the volume of flies equals the volume of alcohol.


Posted by Rui Andrade on 29-09-2007 14:30
#9
Ok, thank you Tony Smile


Posted by John Smit on 29-09-2007 14:57
#10
Ehh. slight correction to the identifications.
Top one is C. intermedium and the second one is C. octomaculatum, to my opinion.

John

Posted by Isidro on 29-09-2007 16:09
#11
Tony Irwin wrote:
No problems, if they're from the same locality on the same date! Wink


But a thread of mine with six species in the same genus (Bombus) and same locality and same date, was closed before begin... I thinks that is better post one species per thread...

Posted by crex on 29-09-2007 17:13
#12
Isidro wrote:
Tony Irwin wrote:
No problems, if they're from the same locality on the same date! Wink


But a thread of mine with six species in the same genus (Bombus) and same locality and same date, was closed before begin... I thinks that is better post one species per thread...


A jar and a thread is not the same thing Pfft

Posted by Rui Andrade on 29-09-2007 17:28
#13
John Smit wrote:
Ehh. slight correction to the identifications.
Top one is C. intermedium and the second one is C. octomaculatum, to my opinion.

John


I'm very confused :-S.
John, can you explain me your hunch? What caracteristics you see to separate the species?

Posted by John Smit on 29-09-2007 17:48
#14
The abdominal pattern of the first species doesn't fit C. festivum, the spots are to broad. The fact that it has a dark band along the entire front of the wing and the glabrous look of the abdomen and the relative short abdomen make it C. intermedium for me.

The second one, if you closely at the fourth tergite, you see a very small yellow band from the yellow spot to the front of the tergite. Not the lateral side itself, but just before, this is characteristic for C. octomaculatum.

I jope this answers your question

John

Posted by pierred on 29-09-2007 21:04
#15
John,

Thanks for those explanations. It makes us do some progress.

Posted by Rui Andrade on 29-09-2007 21:15
#16
Thank you very much, John Smile.

Pierre is right, those explanations help us a lot.