Unknown fly

 Unknown fly

Observation - Unknown fly. Description: Whilst out for walk last week came across hedgerows full of what I think was wild angelica (not sure on plant id , it was one of the umbelliferae)On each head there were many insects feeding including many of these. Quite large flies similar to a horsefly

Whilst out for walk last week came across hedgerows full of what I think was wild angelica (not sure on plant id , it was one of the umbelliferae)On each head there were many insects feeding including many of these. Quite large flies similar to a horsefly.