Diptera.info

Posted by Stephen on 03-09-2006 14:32

There were many many flies on this section of lake shore and I suspect a fisherman had cleaned his fish here.

Maybe not enough detail to say for certain, but maybe two species of Calliphoridae and one Muscid?

Posted by Zeegers on 03-09-2006 15:38

Well, I agree with Calliphoridae and Muscidae.
The Calliphoridae seem to be 1 male and 2 females of Lucilia, they could very well represent the same species.
The Muscidae would be something like Morellia,
but remember this is the Old World speaking !

Theo Zeegers

Posted by Stephen on 03-09-2006 18:06

Thanks, Theo! We in the New World do share Morellia with you. According to nearctica.com we have three species, M. micans, M. podagrica, and M. scapulata.

On the Calliphorids, the male looking more robust I had thought it might be a different species for that reason. Another thing I wondered about is that the two females are holding their wings differently from the male, but perhaps that is not an important thing?

Thanks again for your help.

Posted by Tony Irwin on 03-09-2006 23:32

I hesitate to disagree with Theo (experience tells me this is not a good idea! ;)), but I don't think the females are Lucilia. They're certainly not the same species as the male - much smaller scutellum, and a different bend in vein M (just visible on the upper fly). They may even be muscids - something close to Dasyphora. The angle at which they hold the wings is not always a good character, but it is a clue. In both Muscidae and Calliphoridae there are genera which tend to hold the wings out, and those which tend to overlap them.
I agree about the Morellia.

Posted by Stephen on 04-09-2006 11:26

Ah well the problem with this kind of group shot is that you don't get as many details for identification as you would when zooming in on a single fly. Thank-you Tony and Theo for the comments. I am slowly learning what characters to look for!

Question: Is it generally safe in Muscidae and Calliphoridae to say that the flies with the eyes touching up above are males, and if the eyes are well-separated they are females? I have never been clear on which families (if any) this rule is true for.

Edited by Stephen on 04-09-2006 11:29

Posted by Zeegers on 04-09-2006 13:07

Well, Tony,
in case on non-Tachinidae your judgement is easily superior to mind.

Like in this case

Theo

Posted by Xespok on 04-09-2006 15:36

THe larger species could be a Lucilia the smaller species a Phormia. But do not consider these IDs anywhere near sure.