Sooty Mold is a form of fungus that grows on the sugary honeydew secreted by AphidsSee a picture, learn to identify, and read about Aphid houseplant pests in the Glossary of Houseplant411.com., scaleSoft Brown Scale is the most common scale that attacks indoor houseplants especially ficus, ivy, spider plants, ferns, aralia, and schefflera. It appears as small bumpy brown spots that appear to move. As the scale sucks on the sap of the plant it secretes a sticky substance called honeydew. The honeydew attracts black mildew. Because of the shell-like exterior, sprays are only partially effective against scale. Wipe off the lines of brown oval bumps with your finger, a cloth, or a child’s toothbrush then spray the plant with Neem Oil. Use the Green Solution to clean off the black mildew.s, the whiteflyLearn how to identify and treat the plant pest called Whitefly at https://www.houseplant411.com/glossary/whitefly-plant-pests, and other insects that suck the sap from plants. Sooty Mold is an unsightly black powder that can quickly coat the leaves of a plant in just a few weeks. The fungus itself doesn’t really harm the plant; it just ruins the plant’s appearance. Sooty Mold can be prevented by getting rid of the insects that secret the honeydew that attracts the Sooty Mold.