Here is a list of predatory mites that are currently available online. I personally have used Phytoseiulus persimilis myself and found them somewhat effective. The trick is to introduce them in large numbers dispersed around your plants, as soon as you spot mites. You must not use Neem oil or pyrethrum while your predator mites are active. Phytoseiulus persimilis can be seen quite easily by the naked eye. They are bright red and move quickly. One hassle with them is that they get on your arms as you tend your plants and the little suckers bite you leaving tiny weals.
Phytoseiulus persimilis. This bright orange predator is native to the tropics of South America. It does best in a humid environment of 60 to 90% relative humidity. Does best where tempertures remain below 90 degrees F. Persimilis is sensitive to high tempertures and low relative humidity. A humidity of 60% or lower has a negative effet on the hatching of the eggs and the development of Persimilis. If spider mite problems occur in a hot and dry environment, Longipes or Californicus will provide better control than Persimilis. Persimilis can reduce spider mite population to very low numbers in two to three weeks. Since Persimilis are faster and stronger than their prey they easily catch and eat them. When released they smell their prey, then move quickly throughout the plant. Persimilis work best from tempertures of 50 t0 90 degrees F. They then die from lack of food. In situations where the pest reinfest the plants, we suggest introducing persimilis every 3 to 5 weeks or introducing either Occidentalis or Californicus in combination with Persimilis.
Galendromus occidentalis is a very versatile mite predator and tolerates high temperatures low and high humidity (40-85%) well, both indoors and out. Does best in warm weather (80° to 110° F). Tolerates low humidity of inland valleys. Does not do well in cool coastal areas. Goes into diapause (hibernation) in colder temperatures. Recommended for greenhouses only if plants are maintained as low as 40% relative humidity. It is native to California and has ben researched for spider mite control in almonds, grapes, and many other ornamentals and plants. This predator is well adapted for outdoor use and can perform in hot situations where humidity remains above 40%. Use G. occidentalis to control spider mites, two spotted mites, Russet mites, and others on gardens, greenhouses, and orchards of all types. Adults eat 1-3 pest adults or up to 6 pest eggs/day. Release rates indoors, 2-3/sq. ft. bi-weekly, 1-2 applications; outdoors, 5,000-20,000/acre, bi-weekly, 1-2 applications.
Neoseiulus californicus predatory mites consume their prey at a more leisurely pace than do their friends Mesoseiulus longipes and Phytoseiulus persimilis, one adult or a few eggs per day, they can survive longer under starvation conditions and can also live on a diet of pollen. In plants where it is very hard to detect the first spider mites, Californicus may be introduced preventatively, Completes a generation in one to two weeks depending on temperature (12 days at 64º F, 4 days at 90º F). The female lays about 3 eggs per day for two weeks and lives about 20 days. At 77º F the female can consume 5.3 spidermite eggs per day. Does best in warm humid conditions, but will also tolerate low humidity (40% - 80% RH at 50° - 105°F). Occurs along coast and inland valleys of California. PESTICIDES: Susceptible to pesticides. Avoid using any pesticide one week prior or one week after releasing predators. STORAGE: Highly perishable, should be used immediately upon delivery. If storage is absolutely necessary, refrigerate at 40°-50° F. (6°-10° C). Not to exceed 3 days, to minimize mortality. They are not canabalistic and survive shipping very well. Release 1 - 4 per plant or 1 - 2 per square foot in greenhouses at the first sign of spidermites. Use 10,000 per acre in field. Later releases will require much higher numbers to be effective. Releases of californicus can be made when Spider mites are present and laying eggs. even if no spider mites have been found yet. N. californicus need a minimum of 40% humidity and ideal temperatures 60-90 degrees F. Can tolerate temperatures up to 105 degrees F. Works great in gardens and greenhouses.
Mesoseiulus longipes is similar to P. persimilis but can tolerate lower humidity 40% at 70 degrees F. but requires higher humidity as tempertures increase. M. longipes are effective in temperatures up to 100 degrees F, although a comparable increase in humidity is required. Apply these predators in warm greenhouses and interiorscapes with artificial lighting. The lifespan of the adults, the form in which they are shipped, is 34 days. Release rates indoors, 3/sq. ft. bi-weekly, 1-2 times; outdoors, 5,000-20,000/acre, bi-weekly, 1-2 times.
A spider mite web may be so small it is only seen under a magnifying lens, a microscope or Macro lens.
The following spider-mite images were contributed by: Squilly