Posted by treebeard on 28-03-2017 17:34
#2
I think you are right. Brachypalpus laphriformis has a dark arista, while B. valgus has a white one. Chalcosyrphus eunotus is also similar, however, it has a dull thoraic dorsum, while your specimen has a shiny one.
On top of that, B. valgus is a spring species, Chalcosyrphus eunotus is not.