Hoverfly on Marjoram (or similar herb) in dry grassland.
No interactions present.
Habitat is of little use, as both species are found all over the place, at this time of year. I saw over 100 trivittatus at the coast on Sea Lavender, a couple of weeks ago; they are also regular on local dry heathland, at the moment. I suspect this is a female pendulus, but I would leave it at genus only, as you have done.
My Flickr photos...
Lat/Lng: 53.2, -1.8
OS grid ref: SK1473