Flies undertake epic migrations that may be vital for pollination

Many species of flies migrate for hundreds or thousands of kilometres, often in vast numbers, a review of the evidence shows. These largely overlooked migrations mean flies may play a key role in many ecosystems, in particular by carrying pollen for much longer distances than other pollinators such as bees.

This role could be especially important as the world gets hotter, says Will Hawkes at the University of Exeter in the UK, by allowing plants to acquire genetic variants from…