Helophilus pendulus is one of Britain’s commonest and most widespread hoverflies, found around fresh water pretty much anywhere. Several of these have been present at the ponds in our garden in the last few days, and the species will probably be present all summer. Like most hoverflies, it doesn’t have an English name (yet),
In hoverflies, the sexes can usually be told apart easily, as males have their eyes touching on the top of their head, whereas females don’t. Helophilus is an exception: males and females have their eyes separated.
Helophilus hoverflies can be told apart from most other groups of hoverflies found around Bristol by the pronounced longitudinal yellow stripes on the thorax. Two other species of Helophilus are also found locally: H. hybridus is scarcer; males don’t have the narrow black band across the middle of the abdomen (leaving clear yellow panels running down each side). H. trivittatus is bigger, with paler yellow areas, and can be quite common in late summer when numbers are swelled by migrants. When seen close-up, both species have other useful identification features: a very good photographic identification guide to hoverflies – Britain’s hoverflies: an introduction to the hoverflies of Britain, by Stuart Ball and Roger Morris – was published recently and gives much more detail on how to tell these species apart.