#3
Indeed, and the genus is Xylota.
Could be Xylota vecors, but I don't know if there are more lookalikes!
Greetings
#5
This is a male of Xylota or Chalcosyrphus. Not Xylota vecors (nowadays Chalcosyrphus vecors), that is a black species with red legs (like European C. femoratus). Unfortunately I do not know any species of Xylota/Chalcosyrphus with such a clear pattern on the fourth abdominal segment.
Wouter