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Hello all

This is my first post here. I'm an amateur entomologist, with a keen interest in photography.

I'm trying to help a colleague in identifying the suprasquamal ridge on flies. We've got a few key books, but the ridge is often depicted on fairly basic (and frankly confusing) line drawings.

In an attempt to figure out just where to look, I've taken a few photographs of some blow flies in the area we know to be looking, but aren't entirely convinced what we think could be the ridge, is in fact the ridge. If anyone can confirm or point us in the right direction this would be greatly appreciated:

My first attempt, it's not the brownish structure about "8 o'clock" from the base of the halter is it?

Fly 1 by Chris_Moody, on Flickr

Different species, could it otherwise be the structure about 3 o'clock from the base of the halter, with hairs at the bottom?

Fly by Chris_Moody, on Flickr

Different angle, I suspect the calypter may obscure the ridge?

Fly 4 by Chris_Moody, on Flickr

Again, any help will be greatly appreciated, thank you all!

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Useful post, I've never been able to find it either.

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i have always taken it to be this part... someone correct me if wrong

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Interesting! So it is the structure at the base of the calypter that joins on to the main body of the fly?

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Supra means above. So the ridge is above the squama. Picture "fly 4" is getting close to it, but you have to bent the squama it bit downwards to see the ridge. the ridge is visable from a dorsal view. If you have access to specimens of Miltogramma punctata that could be helpfull because that species has clearly visible hairs on the ridge.

Liekele

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That is good to know, thanks. I find the terminology and synonyms a bit confusing! Only just realised squama and calypter are one and the same!

If I get the time tomorrow or the day after I will see if I can get another photo from another specimen, dorsal view, with the squama/calypter bent down. I can get a bit closer than in those photos, but not knowing quite where to look made doing so a bit pointless/difficult!

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Hello all again

I had a fresh specimen given to me yesterday, so I've got a different angled photograph. I tried to pin the wings back and manipulate the calypters to get a dorsal view, but it proved a bit too fiddly with the time I had.


Bluebottle Calypter by Chris_Moody, on Flickr

Is the orangey structure to the lower right of where the wing attaches to the body (and above the calypter), the ridge?

Many thanks for your help!

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It is.

Liekele

b.t.w. very nice pictures.