African violets are gorgeous houseplants that come in a variety of colors, including purple, pink and white. A consistent problem for the plant, however, are various types of houseplant pests. It can be difficult to get rid of plant pests without killing the African violet. Some growers succeed in keeping the African violet plants alive, but find that they have not succeeded in getting rid of the plant pests.
There are three different categories that the houseplant pests fall into: chewing, sucking or nuisance pests. Spider mites fall into the sucking pest category. The spider mite does not attack the center of the African violet plant like a similar mite, called cyclamen mites. The damage that the spider mite does--to the leaves--is usually pretty severe. You'll know when your African violet has been attacked by spider mites, because you'll spot bleached out or yellowed spots on the leaves. The spider mite may have moved from another plant or flower that you had in the house, such as marigold plants, ivy or mums. The easiest way to avoid spider mites is not to keep these types of ornamental plants near your African violets.
If you suspect that your African violet has spider mites, but aren't sure, hold a piece of white paper underneath the discolored leaf and gently tap and shake the leaf without breaking it off. You may want to do this outside in the sunlight. If you see small black specks fall onto the piece of paper and the specks appear to be moving, you have spider mites.
General Spider Mite Prevention
The first step is to keep other plants that tend to harbor spider mites away from your African violets. Wash your hands extremely well before handling an African violet after handling an ivy plant, marigold plant or mums.
Dryness is the number one culprit when it comes to spider mites and African violets, so preventing dryness is an important part of preventing spider mites too. To retain moisture, try to keep them away from the afternoon sun and out of arid weather. A humidifier may also be beneficial to African violets. Keep one on near the African violet for a few hours during the afternoon each day.
If prevention doesn't do the trick, you may want to try some mild solutions on your African violets. Mix 5 tbsp. of liquid dish soap with one gallon of water. Put the solution into a spray bottle and spray the African violets down two to three times a day for several days.
Another homemade insecticide is to mix one cup of water with one cup of rubbing alcohol in a spray bottle. Spray down the entire plant once a day, making sure to spray the underside of the leaves. This solution will evaporate very quickly, because of the rubbing alcohol, so it should not damage your African violet. This application will also have to be repeated several times, but if neither works, you may consider purchasing a spider mite insecticide made specifically for African violet houseplants.