Spider mites like it warm and dry – exactly what it’s like in many homes in winter or outdoors in the heat of the summer. These tiny insect-like arachnids (closely related to spiders) are nearly invisible to the human eye, but you can definitely see the damage they do.
The mites suck plant juices from houseplant leaves, causing them to turn yellowish with a silvery sheen, and often to drop off. Outdoors, the entire canopy of the plant will have a bronzed, speckled appearance prior to leaf drop. They usually congregate on the undersides of the leaves, and if the infestation is severe enough, you’ll see the webbing there. Another way to test for mites is to hold a piece of white paper under a branch and shake it. If you see any tiny specks fall on the paper, and after a few seconds the tiny specks begin moving, those are mites.
Spider mites like dusty plants, so it helps to frequently wipe down leaves with a damp cloth. But for a sure-fire method, use a product that controls spider mites and is labeled for use on houseplants.