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Hello!

Is this photo good enough to ID this fly?
I think it may be Calliphoridae, Pollenia rudis (female)?

Please, if possible, could you tell me if I've got the sex right too.

Thanks, Ginks

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It is indeed a Pollenia, possibly or even likely P. rudis, since it is very common, yet it is not possible to say with 100% certainty.

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Yes, correct sexing.

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Jason, you can see that the fly is a female? I cannot, how do you see it?

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Hello!

I used the spacing between the eyes to determine the sex of the fly. I know this technique cannot be used for every species.

Is it OK for this species?

Best wishes,
Ginks

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No, it is not, sorry.

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You really have to look at the genitals. With Calliphoridae generally speaking, there are few characteristics to separate the sexes. (as far as I know, I am not too familiar with the family)

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Maybe this helps? :D

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Oops, interesting. Please, add that really you cannot say that when eyes are touching it is male and when not it is female. Even for Syrphidae it is not always the case (Helophilus).

But this is really entertaining for me. I was never aware of it of calypterates.

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I decided to look at the other Calliphorids, because I was pretty convinced that the separation of the eyes is not a good characteristic, but it is not true. Also at Calliphora! For me funny, that I never realized it.

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I agree Ruud, there are many cases where you cannot tell for sure and caution must be taken. Sometimes people just get lucky. :D

I have another species of Pollenia showing similar ..

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BTW, very nice photo's! I never tried to determine Pollenia's, they are not really my group of flies, but when I see them on a sunny day in the winter on the wall, I always like to see them.

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WOW!

You've gone to so much trouble over my query, thank you so much. The photos are BRILLIANT... and I'm glad my question has given you a chance to have such an interesting conversation!

When I have my other hat on, I'm an artist, so I'm very observant. I don't know much about flies, but I've been working on IDing hovers for months, so I know some of the pitfalls of trying to sex these critters.

In this case, I got lucky, as you put it!!!

This has been such fun, but it's made me awfully hungry...
TTFN, Ginks

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hahaha, for me it felt, again, as a cold shower and I learnt you only should talk about those families you are familiar with. So no calypterates for me! ;-)

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Don't fret about it, Ruud!

Look on the bright side, you've learnt something, and you've kept a not-so-young-lady amused for a while... that's not a bad afternoon's work in my book!

Nice talking to you, bye!
Ginks

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I am here around for some time. Some people are always chasing me and teasing. Mother, they are not nice! So if people like Jorge Almeida appear or Roger Thomason, the Shetlander, who is sometimes as evil as Jorge.....beware!

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It's queries like this that are educational for all Ruud, you have done many people a favour. |t

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Jorge and Roger are not like that.....;-)

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The eyes - with a lot of scrutiny! Though, your point is correct with a lot (most?) of calypterates.

For me when it comes to calypterate males with widely-separated eyes they usually have the interfrontalia the same or a comparable width to the parafrontalia, and with such girls as you see here the interfrontalia just below the oculars is wider then the parafrontalia. That said, I don't doubt there are exceptions - probably more so, than parrallels with my reasoning! Asides from this, female insects in such cases are usually wider, slightly more rounded and the tip of the abdomen looking less likely to contain male genitals! As I say, there are always insects around to chuck spanners in the works.

nice to 'talk' to you anyway, Ruud, I've seen you around frequently.

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Not so true, Jason. In the past I visited diptera.info more frequently.At the moment I am almost every evening busy with determining flies for malaise traps. Only as a break, so now and then, I pay this excellent site a visit. I like to people active on it a lot. Paul is doing truly a fantastic job with it.

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Sounds like a good way to while-away the evenings anyway - just the sort of pursuit you want regular identifiers involved in for the sake of continuing to learn and remaining in-tune with all that's currently 'on-the-wing'.

Now, just to find another species other than that wretched lutea, in the Lonchoptera genus!!