Flower Fly or Hover Fly of the family (Syrphidae)

Likely Syrphus ribesii

Note apparent yellow upper legs

Known as a flower fly in North America and a Hover fly in Europe there are numerous species of these critters that emulate the behavior of bees. Very similar is the Syrphus Tovus which is described as having hairy eyes and black legs. The S. ribesii is described as having yellow femurs. I have assigned the S. Ribsii based on the second and somewhat blurry photo that appears to disclose yellow upper legs.

This insect is somewhat smaller than a bee, and for reference, the flower shown here is a Tansy Ragwort, a local noxious weed.

Additional information: see Wikpedia - Hoverfly