A medium sized hoverfly with black and white stripes on its thorax, and a yellow and black abdomen.
No interactions present.
Thanks to Ophrys for his detailed notes on others' Helophilus species!
Lat/Lng: 51.03766, -1.3505
OS grid ref: SU456266
On blackthorn blossom, bridle way from Oliver's Battery to Yew Hill, Winchester.