@Hejor1 @MichaelMulvaney This is a very interesting sighting. I knew nothing about this genus of hover flies and certainly had no idea that they are ant parasites. From a quick search it looks like there is not much information on the host ants, which here I would guess are Technomyrmex. When I get back in the office (some weeks away) I’ll do a bit more research. How did you know they were Microdon pupal cases Hejor?