Phytoseilus persimilis
Two-Spotted Spider Mites
43-90 °F.
60-90% Humidity

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  • Regular price $20.99



These are live insects and MUST be shipped OVERNIGHT. No USPS or ground shipping. 

Target Pests: 
Two-Spotted Spider Mite (Tetranychus urticae).

Description: 
“Persimilis” is a tropical predatory mite that was one of the first greenhouse biological control agents available commercially. Adults are bright reddish orange, with long legs and pear shaped bodies, 0.5 mm long. Immature predators are a pale salmon color. Eggs are oval and 0.3mm long. Both adult and immature predators move rapidly over the leaves and both feed on two-spotted mite eggs, nymphs and adults. Unlike its prey, Persimilis does not spin webbing.

Product Information: 
Persimilis is available in a granular carrier (usually vermiculite) or on bean leaves. Persimilis in vermiculite is available in high -density mixtures and low density formulations. Low-density formulations are only for use before spider mites are detected in the crop. Once spider mites are detected, it is essential to establish predators as soon as possible by introducing Persimilis either on leaves.

Persimilis should be applied the same day they are received, as the quality of the product drops with storage. If persimilis must be stored, hold only at 10-15°C (50-59°F). Temperatures above or below that range cause mortality.
When Persimilis are refrigerated, they tend to clump together. If the package is cold, lay the container on its side at room temperature (out of direct sunlight), for 15-20 minutes to allow the mites to warm up and move apart.

Release Rates: 
1 per 5 sq.ft., or 20 Persimilis per infested leaf, weekly, as needed. Apply predators to each infested plant. 
For larger areas, use 60,000/hectare (24,000/acre).
Persimilis is most effective when applied at the first sign of a two-spotted mite infestation. Because of its high reproduction rate, Persimilis usually exhausts its food supply and eventually dies out, therefore, repeated introductions are recommended until all sites with spider mite infestations have Persimilis present.
Greenhouse tomatoes --Apply at a ratio of 1 predator to 10-20 spider mites. The glandular hairs on tomato leaves are toxic to Persimilis so females will lay fewer eggs than on other crops. For best results, use the predators shipped on bean leaves as these are more easily to apply to tomato leaves than vermiculite.
When predators are found on each infested leaf, it usually means that the biological control program will be successful. It may take another 2-6 weeks for new plant growth to show improvement, depending on growth rates.

Lifespan:
A complete life cycle takes from 5 days (to 30°C (86°F)), to 25 days (to 15°C (59°F)). There are 4 times more females in the population than males with a ration of 4:1. Females lay 2-3 eggs per day for an average of 60 eggs over their 35-day lifetime. The eggs hatch in 2-3 days. They are oval and twice the size of two-spotted mite eggs. Newly hatched predators do not eat, but later stages and adults feed on all stages of prey. Each predator consumes between 5-30 prey (eggs or mites) per day. Persimilis does not diapause, therefore, remains active year-round in greenhouses.

Strategic Considerations: 
If spider mite numbers are high (there are visible webbing and clusters of mites stringing down from leaves), use a compatible pesticide, such as fenbutatin oxide (Vendex®) or insecticidal soap, to reduce pest numbers before releasing predators. 

Persimilis needs relative humidities greater than 60% to survive. In low humidity conditions, raise the humidity by lightly misting plants or wetting walkways.
The pesticide, fenbutatin oxide (Vendex®), can be used with Persimlis for additional control of spider mites if “hotspots” develop. It does not harm Persimilis, but avoid over spraying, which reduces the Persimilis food supply and their ability to reproduce. Spreader-stickers, supreme oils and soaps are harmful to the Persimilis contacted by the spray, but have little residual activity.