Pest control The UN Food and Agriculture Organisation (FAO) has launched a smartphone app to help combat a maize-eating insect that has infested millions of hectares of crops in Africa. According to Reuters, fall armyworm – now present in all but 10 African countries – poses a threat to the food supply and income of more than 300 million people, and is what drove the development of the app. Mapping the spread of the infestation is key to fighting the problem. Farmers check 10 plants in a row in five different locations in their field, and mark in the app whether the armyworms’ larvae are absent or present. The app then calculates the infestation level. Once that data is uploaded to the FAO’s servers, it goes to a web-based platform where researchers and others can view it. ‘The app is simple and intuitive to use, and the transmission costs are not high and not covered by the farmer,’ says Keith Cressman, who leads the app development team. 20 March 2018 Image: Gallo/Getty Images