Guests for lunch

I noticed that the Borage is covered in blackfly today, then spied this hover fly (bee, wasp??) busy eating something. Hoped it was a handful of blackfly but alas he was only sucking the juice out of the leaf. On other photos I took, I noticed that there are other smaller flies and tiny spiders on this plant all tucking in together.
I grow the Borage to attract bees to my runner beans and for the lovely blue flowers that I use to decorate salads. But as it is covered in blackfly I fear the time has come for the compost!