Hoverflies in the genus Parhelophilus look similar to those in the genus Helophilus but they are generally smaller, rounder, more orange and have hairs on their abdomen.
Five species occur in Europe.
This is either Parhelophilus frutetorum, which can be recognized by the row of black hairs behind the eyes, or Parhelophilus versicolor which has yellow hairs behind the eyes.

While in most other hoverflies, males can be easily identified by their holoptic eyes (eyes touching at the top of their heads) and females by their dichoptic eyes (eyes are further apart), 
the eyes of hoverflies in the Subtribe Helophilina with stripes on top of the thorax (i.e. the genera Helophilus, Parhelophilus, Anasimyia, Eurimyia and Lejops) are separated in both sexes, in the male a little less than in the female.
In these genera, the inner edges of both eyes of the males run more or less parallel, whereas in the females they diverge but you can only see this properly in a frontal face photo.

Hortobágy-Halastó, Hortobágy National Park, Hungary, 2 May 2019