Sooty mold is a combined expression that grows on the honeydew dropped by many sap-feeding insects (most commonly aphids, scale and whiteflies). The honeydew is a sugary liquid that the insects excrete as waste. Honeydew is secreted on the surface of leaves in the process of feeding and the spores of fungus in air grow the coating of sooty mold. The leaves, branches and fruits turn black. The use of flonicamid + difenaconazole is actually helpful to prevent the damage.