New species of mosquito threatening malaria fight

Two strains of Africa's most notorious malaria-carrying mosquito are evolving into new species, research has shown.

The discovery has implications for combating the disease, since it means the insects could become immune to control methods.

Scientists studied the Anopheles gambiae mosquito, which is chiefly responsible for spreading malaria in sub-Saharan Africa.

They found two strains were rapidly diverging in their genetic make-up, despite appearing physically identical.

Dr Maria Lawniczak, a member of the team from Imperial College London, said: "From our new studies, we can see mosquitoes are evolving more quickly than we thought and that unfortunately, strategies that might work against one strain of mosquito might not be effective against another.

"It's important to identify and monitor these hidden genetic changes in mosquitoes if we are to succeed in bringing malaria under control."

The changes had occurred in areas likely to affect development, feeding behaviour, and reproduction.

A further study comparing the two strains showed they seemed to be evolving differently. This was thought to be in response to different environmental factors such as larval habitats, infectious agents and predators.

Co-author Professor George Christophides said: "Malaria is a deadly disease that affects millions of people and causes one in every five deaths among children in Africa.

"We know the best way to reduce the number of people who contract malaria is to control the mosquitoes that carry the disease. Our studies help us to understand their makeup."