A recent study has described the Migrant Hover Fly Eupeodes corollae (Fr. Syrphe des corolles) as a flying 'multitool', which offers pollination, can act as a vector for beneficial microbes, and is a biological control for grey mould disease in strawberries. Wow! Plus their larvae eat aphids!
Female Migrant Hover Fly.
Scientists in Sweden used the hover flies to carry the yeast Metschnikowia fruiticola between strawberry flowers in greenhouses so it would attack the grey mould Botrytis cinerea. At the same time the hover flies pollinated the strawberry flowers. The flowers pollinated by the hover flies produce better quality fruit that is bigger and a more symmetrical consumer pleasing shape. Their results showed that the hover fly activity on the flowers significantly reduced grey mould on the strawberry fruit once harvested and in cold storage. This occured even without the yeast biological control, but was even more pronounced when the yeast was present.
This species is native to Europe, North Africa and Asia, and quite abundant. With the presence of active adults and larvae you can practice interated pest control in your own garden, and enjoy these little natural gems.
Mating Migrant Hover Flies in our garden.
The Migrant Hover Fly is, as the English name suggests, a migratory species and one of the two most abundant species of hover fly in Europe. Some years there will be massive numbers crossing the Channel from France to Britain. The adults are about 11 mm long, with yellow comma shaped marks on their abdomens.
Further reading: https://link.springer.com/article/10.1007/s10340-025-01971-6
