BBKA Forum

Yesterday evening I noticed that a hive of bees was being attacked by flies. The flies were darting in and trying to settle on the abdomen of the bee, and the bees were defending themselves. But every now and then a fly manages to cling to the abdomen of the bee for some time. This behaviour seems very typical of parasitic flies laying eggs on the bees - but I cannot find any description of parasitic flies like this in the UK.

What are these flies? Are they common? Are attacks like these common?
I recorded several minutes of video, and also extracted some frames from the video
The video and the extracted video frames are on the page linked below

https://peter-thomson.com/bees/index.html

I would suggest contacting your local seasonal bee inspector in the first instance

I opened a water filtration unit last week and was attacked by midges.The speed and severity was a shock even after the satanic colony of bees I had the misfortune of stewardship last year.

I've not experienced flies as your video.
Does it make any difference if the black covering is taken off the colony?

Another hive with the same cover wasn't being attacked, and the flies were not present at all at the entrance at the other end of the hive where the bees were guarding inside, but not using it as an entrance and exit.

There were no flies around another hive entrance that was covered with a fine mesh to allow bees to ventilate but not to exit.
they were specifically targetting the bees and not landing on the cover away from the bees. Hovering in front of the entrance and then darting in when a bee looked exposed.

I wonder if it is Senotainia tricuspis Meigen ?

I am not able to see any pictures or videos but Beewolf springs to mind..