They come from warmer climates and can come into your home (or outdoor plants) by bringing home infested plants from a nursery. They spread from plant to plant and feed off of growth points. They are white, tiny little guys that form cottony nests where they are feeding. They can even live in the roots.
Additionally, where can I find mealy bugs?
How to Identify Mealybugs. Soft-bodied, flat and waxy, mealybugs can also be identified by their oval shape and body segmentation. These insects can also resemble cottony spots, especially as females lay eggs encased in a waxy cover.