What are the tiny, sticky, cottony balls on houseplant leaves?

Mealy Bugs are one of the most annoying and destructive pests that attack houseplants. These tiny sucking insects look like small pieces of cotton. The bugs suck the sap out of a plant; they especially love the tender new growth. As the plant loses sap, leaves get spots, some turn yellow, leaves drop, stems get weak, and the plant just doesn’t grow well. While feeding on the plant they secrete a sticky substance called “honeydew” which causes another problem because it attracts “sooty mold.” The mold covers leaves and stems ruining the plant’s appearance and interfering with photosynthesis. When mealy bugs are immature and crawling, use Yellow Sticky Cards to trap them. Once they mature, spray them with the chemical free “Green Solution”; 1/2 water, 1/2 alcohol, a few squirts of a liquid biodegradable soap, and a tablespoon of mineral oil. Be sure the plant is well-watered and not in the sun when you spray. Repeat this treatment every 10 days for a month to kill any eggs that might hatch later. On furry leafed plants dip a Qtip in the Solution and wipe the bugs off individually. Do not spray the entire leaf.

Picture of Mealy Bugs on a Houseplant