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Here is the added picture, now enlarged, maybe this helps?

All three pictures taken at 1:06 p.m., image files 1430984, 1430988 (the two I glued together) and 1430991 (the second one I posted) and I didn't take a note that I took pictures of 2 specimens (which I would have done in such a case) - if there are still doubts left ;).
Btw, what's the matter with the first two pictures? Is there any inexplainable change?

The only thing that could have happened is that maybe I twinkled and just in that moment one mean Bibio came from beyond, kicked the other one off its resting place and sat down itself, imitating its mate's gestures as if nothing had happened... ;)