Marmalade hoverfly on a marigold

In insect terms, nothing says summer in the garden to me quite like hoverflies. Bumblebees come pretty close. But I love hoverflies and this one is a real delicate beauty. I think it is a female marmalade hoverfly, Episyrphus balteatus. Apologies if I've got that identification wrong! It is among the very few species of flies capable of crushing pollen grains and feeding on them. This one appeared to be feeding on pollen on a marigold flower in my mother's East Lothian garden. According to Wikipedia, the larva of this species is terrestrial and feeds on aphids, making this hoverfly, as with so many others, a friend to gardeners!.