Chemical Control
"Spider mites frequently become a problem after applying insecticides. Such outbreaks are commonly a result of the insecticide killing off the mites’ natural enemies but also occur when certain insecticides stimulate mite reproduction.
For example, spider mites exposed to carbaryl (Sevin) in the laboratory have been shown to reproduce faster than untreated populations. Carbaryl, some organophosphates, and some pyrethroids apparently also favor spider mites by increasing the level of nitrogen in leaves. Insecticides applied during hot weather usually appear to have the greatest effect, causing dramatic spider mite outbreaks within a few days.
If a treatment for mites is necessary, use selective materials, preferably insecticidal soap or insecticidal oil. Both petroleum-based horticultural oils and plant-based oils such as neem, canola, or cottonseed oils are acceptable. There are also a number of plant extracts formulated as acaricides (a pesticide that kills mites) that exert an effect on spider mites. These include garlic extract, clove oil, mint oils, rosemary oil, cinnamon oil and others. Don’t use soaps or oils on water-stressed plants or when temperatures exceed 90°F. These materials may injure some plants, so check labels and/or test them out on a portion of the foliage several days before applying a full treatment. Oils and soaps must contact mites to kill them, so excellent coverage, especially on the undersides of leaves, is essential, and repeat applications may be required.
Sulfur sprays can be used on some vegetables, fruit trees, and ornamentals. This product will burn cucurbits and other plants in some cases. Don’t use sulfur unless it has been shown to be safe for that plant in your locality. Use liquid products such as sulfur and potash soap combinations (e.g., Safer Brand 3-in-1 Garden Spray) rather than sulfur dusts, which drift easily and can be breathed in. Don’t use sulfur if temperatures exceed 90°F, and don’t apply sulfur within 30 days of an oil spray. Sulfur is a skin irritant and eye and respiratory hazard, so always wear appropriate protective clothing."
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7405.html
