Hoverfly on Plum tree leaf

Hoverfly on Plum tree leaf

Observation - Hoverfly on Plum tree leaf. Description: As far as my skills go, there are two or three species this could be. It's getting late, it's not a great photo, and I have a stinking cold: hopefully someone whose brain is still in gear can pin it down!

As far as my skills go, there are two or three species this could be.
It's getting late, it's not a great photo, and I have a stinking cold: hopefully someone whose brain is still in gear can pin it down!