Researchers focused on the Anopheles funestus mosquito, one of the major carriers of the malaria parasite in large parts of Africa. By studying strains of An. funestus known to be resistant to pyrethroids, and comparing their genetic code to those which have no resistance, they narrowed down the genetic differences to a couple involved in getting rid of toxins. Dr Hilary Ranson, one of the lead authors of the research, said: "Routine use of these molecular markers for resistance will provide early warning of future control problems due to insecticide resistance and should greatly enhance our ability to mitigate the potentially devastating effects of resistance on malaria control." Dr Jo Lines, from the London School of Hygiene and Tropical Medicine, agreed and said there was a good chance that the genetic variations would also be found in An. gambiae, the other major malaria carrying mosquito in Africa. He said: "This is very important work. It is currently very time-consuming to test mosquitoes for their resistance to insecticides - this would allow a far simpler and quicker test to be carried out. "This is the first case in which we have been able to pin these genes down definitely."