ABOVE: Episyrphus balteatus, commonly known as the marmalade fly, is one of the most common hoverfly species to be found in Britain, and sports distinctive double stripes on its abdomen.
WILLIAM HAWKES, UNIVERSITY OF EXETER
Every spring, the UK receives swarms of insect visitors from mainland Europe—among them two species of particularly beneficial hoverflies. For the first time, researchers have quantified the sheer scale of their migration and the ecological benefits they bring to Britain.
According to the study, published today (June 13) in Current Biology, the insects consume up to 10 trillion crop-gobbling aphids during their stay, in addition to pollinating British wildflowers and crops. The researchers also report that numbers of migratory hoverflies have been relatively stable over the last decade, and not in decline like many other pollinator species.
“We often think about bees as our major pollinators, but actually the hoverflies and other species of flies are ...