In many regions of the world, mosquitoes are a seasonal pest. In other regions, they carry serious diseases like malaria. The World Health Organization estimates that almost 630,000 people died of malaria-related causes in 2012, mostly in Sub-Saharan Africa. Now, a group of U.S.-based scientists is working to develop a more effective and less expensive mosquito repellent than currently in use. VOA’s George Putic has more.