Heavy sooty mold on a palm leaf.

Sooty mold on a banana (Musa sp.) leaf, associated with coconut mealybug (Nipaecoccus nipae) feeding on the foliage.

Sooty mold on leaves of coconut palm (Cocos nucifera).

Sooty mold on coffee (Coffea arabica) cherries, associated with feeding by green scales (Coccus viridis).

Definition

Sooty mold is black, nonparasitic, superficial fungal growth on honeydew produced by aphids and other phloem-feeding insects.

Discussion

Sooty mold can be a nuisance as an eyesore on plant foliage; it also can block sunlight, which interferes with photosynthesis.