#4
I would not dare to name the species, but it looks as if this might be an intersex (distance between the eyes smaller than in ordinary female but still clearly separate). In intersexes in Syrphini the abdominal tergites usually are dark...
#6
It's a female Leucozona glaucia. And indeed sometimes you see intersexes in syrphids in which the distance between the eyes is intermediate beween male and female. In this case however the eyes of this species are converging like this in the female, so nothing out of the ordinary!
Look at this female, another species in the genus:
http://www.diptera.info/photogallery.php?photo_id=6343
greetings