 In the Pacific islands and in lowland areas of South America and Africa, symptoms of SD are now rarely seen and BLSD has largely supplanted it.SD is more adapted to cooler regions and often predominates at altitudes over 1200 metres while BLSD is rarely seen at such elevations.When spores of "M. musicola" are deposited on a susceptible banana leaf they germinate within three hours if there is a film of water present or if the humidity is very high.