The Fall Armyworm is a moth whose caterpillars attack a wide range of crops in the Americas. It has recently spread to Africa, with potentially devastating results for millions of farmers. Modelling work by Regan Early contributed to an evidence note commissioned by the UK Department for International Development. The report finds that each year the caterpillars could destroy between 8 and 20 million tonnes of the 39 million tonnes of maize that Africa produces, at a cost of up to US$6,187 million. Read the report summary here, and the full report here.