Thread subject: Diptera.info :: Sarcophaga variegata

Posted by Rui Andrade on 18-10-2019 17:34
#1

Hi,

Could this be Sarcophaga carnaria? Comparing the plates in Richet et al. (2011) I find it more similar to S. variegata, but looking at these photos by Chris Raper it looks similar to S. carnaria:
http://chrisraper...5130_o.jpg

What do you think?

location: Porto (Portugal)
date: 27/09/2019

Edited by Rui Andrade on 24-10-2019 23:28

Posted by Rui Andrade on 18-10-2019 17:34
#2

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Posted by Rui Andrade on 18-10-2019 17:34
#3

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Posted by Rui Andrade on 18-10-2019 17:35
#4

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Posted by Rui Andrade on 18-10-2019 17:35
#5

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Posted by PhilC on 18-10-2019 22:11
#6

The last picture is S. variegata, and it looks to me just like Chris's photo of that species so I am rather confused by what you say.

Posted by Rui Andrade on 18-10-2019 23:44
#7

Thank you Phil. In Chris's photo of S. variegata the vesica looks very narrow to me. Also the shape of the ventral plate of my specimen seems to best match the one of S. carnaria. But this is the first time I'm trying to interpret the genitalia of a Sarcophaga so I have no experience at all. S. carnaria is not known from Iberia, so S. variegata also makes more sense from a distribution point of view.

Posted by johnes81 on 18-10-2019 23:47
#8

Hello Rui,

it is certainly not carnaria simply because of the shape and angle of the vesica.

I don't need anyone's photos to judge either species because i've dissected the genitalia of both. I have also properly cleared the genitalia for better viewing, thus, i don't recommend using those photos for your determinations. I will attach a photo of properly cleared genitalia of S. carnaria for reference.

S. variegata will have a flap covering the distiphallus . I see a dark structure twisted toward the end of the distiphallus and the vesica match variegata much better than carnaria.

Best wishes,
John

Posted by johnes81 on 18-10-2019 23:51
#9

ps i own a copy of Sarcophagidae of Fennoscandia and Denmark by Dr. Pape. His work is nonpareil in my opinion and he is a very nice man. I have much respect for Dr. Pape and also Dr. Rognes. I recommend using the material of Dr. Pape for determinations.

Best wishes,
John

Posted by Rui Andrade on 19-10-2019 00:19
#10

Hi John,

Thank you very much for the photo of the genitalia of S. carnaria. I think I was too focused on the shape of the vesica rather than its orientation and the general shape of distiphallus. Now I see that, although the vesica on Chris's photo of S. variegata seems very narrow, the rest of the distiphallus is indeed very similar to my specimen.
I also have a copy of Sarcophagidae of Fennoscandia and Denmark but forgot to have a look because, for the fauna of Portugal, it makes more sense to use Richet et al. But now I'll have a look at that one too. :)

Thank you both very much!

Posted by johnes81 on 19-10-2019 11:15
#11

Hello Rui,

I stick with the work of Dr. Pape when he has material about the species. Otherwise, i fall back to Spixiana.

I have taken a few moments to outline my own dissections using a computer mouse. My hand is too shaky to be precise when using a computer mouse. I think that the illustration is good enough for the purpose of emphasizing the teachings of Dr. Pape. I am not able to convey my knowledge to you, so a good teacher will be able to describe what i am hoping is obvious in my illustrations.

I will attach a jpeg of my quick and dirty illustrations for comparison. I think that the long narrow object at the top of the structure is the paraphallus? anyway, it rides along the phallus on carnaria and flops over the distiphallus on variegata (pale red arrows on my second outline).

I hope that this helps and Best wishes,
John

Posted by johnes81 on 19-10-2019 11:16
#12

illustration with arrows to the identifiable features

Posted by Rui Andrade on 19-10-2019 13:44
#13

Hi John,

Very nice illustrations, thank you for sharing them! If I'm not mistaken the arrows are pointing to a structure called juxta. The difference between the two species is very clear in your illustrations. :)

Posted by johnes81 on 19-10-2019 15:14
#14

Rui Andrade wrote:Very nice illustrations, thank you for sharing them!


Hello Rui,

The illustrations are horrible to me. I've actually won awards for my pencil drawing skills, so i am not happy to post these awful outlines. I also own a pen tablet but i rarely use it. I don't have time to master digital drawing. However, i intend to use my pen tablet to illustrate genitalia in the future.

I also have microscopic photos of S, lehmani and haemorrhoa genitalia. Sarcs are easy to find even at my balcony and inside of my flat. I actually saved a Sarc from certain death because it was trapped in my bird feeder. I came outside at the right time because i am certain that slender-billed birds at my feeder would've grabbed it for a midday snack.

Anyway, someday i will illustrate the genitalia properly using my pentablet and specialized graphics software.

Best wishes,
John

Posted by Rui Andrade on 19-10-2019 22:54
#15

Well, the illustrations were very useful, so I'm looking forward to see the ones made with more care!

Posted by Daniel Whitmore on 07-05-2020 16:06
#16

Interesting thread. Rui's fly from Porto certainly looks like variegata. The vesica is indeed larger than it generally is, but this feature can vary somewhat in this group of species.

Nice illustrations John! You have labelled one as carnaria and one as variegata, but in my opinion both are carnaria.

Pape (1987) and Richet et al. (2011) are excellent references, but I also think Chris Raper's side-by-side photos actually show the differences between the three British species quite nicely.

I recently created a Facebook group about British Sarcophagidae (https://www.facebook.com/groups/459564384954251/) in case anyone is interested. Just yesterday I posted a couplet with annotated photos distinguishing males of S. carnaria and S. variegata, which I attach also here. Other characters can also be used to distinguish the two species, but I think these work quite well.

EDIT: the file is too large to attach, you can find it in the Facebook group or PM me and I'll email it to you if interested.

Edited by Daniel Whitmore on 07-05-2020 16:08