Lookie yonder! A big black cloud comes to Lough Neagh! The swarming of midges on the shores and waters of Lough Neagh every year mark the arrival of Spring. Trillions of flies emerge to swarm and mate over the trees, loughs and roads. To the lay viewer, it may seem a bit of a nuisance. But to Leslie McClarnon, a PhD student at the University of Ulster, they represent the ecosystem of the lough. She discusses her research and how the humble mayfly plays a vital role for the lough's welfare. So if you happen to be on the roads around Lough Neagh in Springtime and see a big black cloud shimmering yonder on the horizon, know that it is a good thing and not some fearful portent.

An Ulster Television Production.