The Bioko form of Simulium yahense was probably the most effective vector of river blindness in the world, and dragged people into poverty by preventing them from working.
On 17 November 1993, Rory Post addressed a meeting of the British Simuliid Group at the Natural History Museum, and first proposed the possibility of eliminating the vector from the island.
As a result this became World Bank policy and part of the mandate of the World Health Organisation African Programme for Onchocerciasis Control (APOC) when it was set up in 1995.
The Natural History Museum was part of the feasibility and planning process - including the environmental impact assessment.
In 2005, APOC succeeded in eliminating the fly from the whole island by carefully controlled application of insecticide - using a formulation and regime designed to have minimal impact on the rest of the ecosystem.
There seem to have been no long-term effects on the environment, but the biting blackflies have never returned and the Bioko form of Simulium yahense is undoubtedly extinct.