Every Monday and Tuesday morning, Bosede Oluwaokere, 48, wakes up at home in Ilorin city in west Nigeria, gets dressed and walks to a nearby stream. She sits beneath a tree and pulls her skirt up around her thighs. For the next six hours she stays in the same spot waiting for a specific type of fly to land on her, so she can catch it using a small plastic tube.
Oluwaokere is a human flycatcher – or human landing catch, as the World Health Organization (WHO) terms it – which is considered the “gold standard” for collecting black flies. Black flies, which breed near rivers, are blood-sucking insects that spread the debilitating neglected tropical disease onchocerciasis, also known as river blindness.
