This hoverfly was photographed sunning on a wooden fence
No interactions present.
Looking at the other observations I wonder if the tail band is less prominant than on E.luiger
The markings on tergite 4 and beyond are very variable, so don't worry about that. The key features are the lunulate yellow spots not meeting the margin and the frons with a bilobed dark projection, typical of female luniger. Females tend to be very dark in early spring.
My Flickr photos...
Lat/Lng: 51.9, 0.9
OS grid ref: TM0127