A new report says targeting mosquito breeding sites is likely to be increasingly necessary to reduce cases of malaria in Africa and Asia.Researchers say that with mosquitoes becoming ever more resistant to insecticides, new approaches will be needed to help control the disease.They include flushing out stagnant water where mosquito larvae grow.More than 600,000 people died from the malaria in 2010, most of them children in Africa.The number of deaths from malaria has fallen by a quarter in the last decade, largely thanks to the widespread distribution of mosquito nets treated with insecticides and the use of indoor insecticides sprays, reports the BBC's global health reporter Tulip Mazumdar.But the insects are becoming increasingly resistant to these chemicals, so a new report by researchers at the London School of Hygiene and Tropical Medicine says authorities should use a method called "larval source management".This is where mosquito larvae found in stagnant water like paddy fields or ditches are killed off by draining or flushing the land before they get a chance to develop.But the report's author, Lucy Tusting, admits there are limitations to the method."It requires in some situations a very intensive effort so in some settings it won't be cost effective," she said."But in others cases you might have a small village with a pond in the middle of it. By removing that you can reduce the number of mosquitoes with very little effort."The World Health Organization says the research is still not robust enough to support this method, and it is not recommended for use in rural areas where breeding grounds are hard to find.The WHO says larval source management should only be used alongside insecticide sprays and nets.