Orange tree with fruit |
A. Spider mites like dry conditions. Since the satsuma is growing in a pot on your porch, it's probably not exposed to rainfall. When you water, you add water to the pot. Right? So, the leaves are seldom exposed to water. As a preventative measure in the future, spray the leaves above and beneath when you water your orange to discourage the mites.
Spraying the leaves with water, especially the undersides, may be enough to get rid of them. If not, there are two pesticides on the market that might do the trick. One is Monterey Bug Buster. The active ingredient is esfenvalerate - a synthetic pyrethroid insecticide. The other pesticide is Trounce by Safer, the makers of insecticidal soap. Trounce contains insecticidal soap and pyrethroids.
As with all pesticides, follow label instructions.