The moths were Silver Y, an immigrant species, and there must have been an influx overnight, as the local wildlife social media sites were all a-flutter with the news. I managed to take a short burst of video to illustrate the abundance, see here. I then returned indoors to swap my phone for a proper camera, the better to photograph the hovers.
|Silver Y, Autographa gamma
|Episyrphus balteatus (Marmalade Hoverfly)