Things You'll Need
Biological insect controls (Stethocorus lady beetles, Georcoris pirate bugs, thrips or
Phytoseiidae cannibalistic mites)
Spider mites are arthropods that live on plants and in the soil. They shred and digest plant residues, burrow through the soil and deposit their waste all of which helps to breed beneficial fungi and bacteria and improve the soil conditions. Spider mites are most active in the warm weather months and mature from eggs to active adults within a weeks time. Mites can become overpopulated in soil when the conditions are dry, the soil is warm and the natural predators of spider mites have become suppressed. Reducing spider mite populations in the soil over the long term requires cultural modifications and re-balancing the population ratio of predatory insects to spider mites by using biological controls.
Water the soil infested with spider mites deeply and regularly as spider mites thrive and are most active in dry soil conditions. Watering the soil well will also help support the beneficial insects that consume spider mites.
Introduce beneficial insects that are natural predators to spider mites, such as Stethorus species of lady beetle known for their particular preference for consuming spider mites. Alternatively, introduce Geocoris species called pirate bugs and or thrips as they both also a nemesis of spider mites.
Introduce cannibalistic mites from the Phytoseiidae species such as Galendromus occidentalis, Neoseiulus californicus or Mesoseiulus longipes, which will hunt and consume spider mites.
Refrain from trying to treat spider mites with chemical insecticides. They have limited effectiveness in killing spider mites and eggs but worse, they kill of the predators of spider mites and can cause the spider mite population to surge when insecticides are introduced.
Check with online dealers of biological control insects to help determine which beneficial insects will be best for your climate, time of year and soil conditions. They can then be delivered to your door.