Spider Mite Control - Persimilis
Spider Mite Control - Phytoseiulus persimilis, Mesoseiulus longipes, Neoseiulus californicus, Galendromus occidentalis
Spider mite larvae, nymphs and adults feed on the underside of the leaves and cause yellow spots,later even yellow leaves. Plant cells turn yellow, which can be seen on the upper surface of the leaf as small yellow spots. This reduces the photosynthetic area of the leaf and the plant gets out of the physiological balance. This results in decreased plant growth and production. Finally the crop may die from the infestation. Nymphs and adults produce webbing that can cause cosmetic damage to the crop. If large numbers of spider mites are present, plants may be completely covered with webs.
- For tomatoes and cucumbers, 1 predator per plant plus 1-2 per infested leaf.
- For other greenhouse crops, tropical plants, and outdoor gardens, 2,000 per 3,000 sq. ft.
- For bedding plants, 1,000 per 10,000 sq. ft.
- For large agri-business, 5,000 - 20,000 per acre depending on infestation.
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