London, Aug 9 (IANS): Scientists have unearthed a vital clue that could help them decimate malaria-causing mosquito populations by rendering males genetically sterile.

They figured out that the female mosquito is unable to tell whether the male it has mated with is fertile or 'spermless' and unable to fertilise its eggs, says a new study from Imperial College, London.

Such a method would rely on females mating unknowingly with genetically modified sterile males and failing to produce any offspring, reports the journal Proceedings of the National Academy of Sciences.

Malaria is a debilitating disease that affects more than 300 million people worldwide every year, and kills nearly 800,000 annually. In Africa, a child dies of malaria about every 45 seconds, according to an Imperial College statement.

The new study focuses on Anopheles gambiae, responsible for the transmission of malaria in Africa, which has been described as "the single most dangerous insect species for mankind" by Professor Charles Godfray of Oxford.

Flaminia Catteruccia from the Department of Life Sciences at Imperial, who led the study, said: "In the fight against malaria, many hope that the ability to genetically control the mosquito vector will one day be a key part of our armoury."

Godfray, zoologist and study co-author from Oxford, said: "This is an exciting time with modern genetics providing a series of new ideas about how to control the major insect vectors of human disease."