Houseplants are susceptible to attack by various pests and diseases. While rarely lethal, pest and disease outbreaks can compromise the aesthetic quality of indoor vegetation. Even tightly sealed houses and conscientious tending cannot always prevent attacks on our houseplants.
One of the easiest houseplant insect pests to recognize is the whitefly. These sap feeders are not really flies - they just look like it. Actually, I think they look more like tiny white moths, but they are the size of gnats, about 1/16 inch long. You might notice them sitting on the underside of an infested leaf, usually the youngest leaves. More likely you will notice the tiny adults when they flutter off the leaf as you water or handle the plant. They are easily disturbed but fly only a short distance before they quickly return to the leaf