They use piercing-sucking mouthparts to puncture the plant tissue and feed on the liquid within the cells. In light infestations the foliage will appear to be speckled with very tiny yellowish-green spots. If the population of mites increases the damage can become severe enough to turn the foliage entirely greenish-yellow and eventually tan or brown. Heavily infested plants often drop their leaves. Close examination of infested foliage may reveal very fine webbing produced by the mites.
Spider mites are tiny and difficult to see with the naked eye on the plant.
A convenient detection technique is to hold a sheet of white paper under a branch and then shake or tap the branch against the paper. The mites, if present, will show up as tiny, slow- moving specks on the paper. Insecticidal soap is available from retail stores under various trade names. You may substitute ordinary dishwashing detergent for the commercial products with little risk of injury to plants. To make your own insecticidal soap spray solution, mix 5 tablespoons of liquid dishwashing detergent in 1 gallon of water.