[Syrphidae] Episyrphus balteatus synonymous - Am I right ?

[Ludovic Arnaud]

Hi all,

Being new with syrphid world, I encountered some troubles with "Episyrphus 
balteatus". Are "Syrphus balteatus", "Episyrphus cretensis", "Episyrphus 
balteatus", "Epistrophe balteata" all refering to the same species, i.e. 
Episyrphus balteatus ? Or do some of them species are distinct species ?

Thank you very much in advance.

Best regards, Ludovic