Even though they are only slightly larger than their prey an adult persimilis (predatory mite) devours up to twenty young or seven adult TSM each day. Under optimum conditions they will multiply twice as fast as spider mites. It feeds voraciously on all stages of twospotted mite, and this has led to its use in a wide range of crops.

persimilis thrives in warm, humid and semishaded conditions. The adult is orange, whereas the younger stages are clear. Both forms are pear-shaped and fast-moving. Its eggs are oval, tinged with orange, and twice the size of spider mite eggs.Although extremely small (approximately 0.5 mm.), P. Persimilis can be distinguished with a hand lens/ magnifying glass. It is fast moving, orange to bright redish orange, has a teardrop-shaped body and long legs, and is slightly larger than its prey. Immatures are a pale salmon color. Eggs are oval, approximately twice as large as the pest mite eggs. (Note: in the winter, the two spotted spider mite may develop a reddish colour, although two dark spots on its abdomen usually distinguish this pest from other mites.)

This species is a specialised predator of web-spinning spider mites. In fact, P. persimilis feeds, reproduces, and completes development only on mites in the subfamily Tetranychidae.
P. persimilis eggs hatch in 2-3 days, and although the larval stage does not feed, the subsequent nymphs and adults feed on all stages of prey. Total time from egg to adult ranges from 25.2 days at 15°C (59°F) to 5.0 days at 30°C (86°F). The adult female may lay up to 60 eggs during her 50 day-long lifetime at 17-27°C. Generation times of from seven to 17 days are possible, depending on temperature and humidity. Due to its tropical origin, P. persimilis does not have a diapause stage and is active year-round in enclosed habitats such as interior plantscapes and greenhouses.

They reproduce more quickly than the spider mites at temperatures above 28°C (82°F), and they feed on all stages of the two spotted spider mite. P. persimilis are very voracious. They have the highest consumption rate of all phytoseiids. However, they absolutely must have spider mite prey or they will disperse and/or starve.

Phytoseiid mites use odors (kairomones) associated with mite-infested plants to locate their prey.

When P. persimilis contacts spider mite webbing, it intensifies its search for prey. P. persimilis has high dispersal ability and its distribution is highly correlated to that of its prey. However, its ability to disperse is dependent on the environment. If infested plants’ leaves touch, dispersal is increased. When the plants have little contact with each other, dispersal is reduced by about 70%. P. persimilis moves upward on the plant in search of prey and disperses when prey is scarce. Nymphs do not disperse easily, and are left behind when spider mites becomes scarce.

Because persimilis predatory mites are such efficient hunters and dispersers, they can cause extinction of their spider mite prey. This is desirable where little or no spider mite damage can be tolerated, such as in ornamental plants. However, in crops where some plant damage is acceptable (e.g., tomatoes and cucumbers), it is desirable to have a stable interaction between predator and prey over an extended period of time.

Typically, P. persimilis will eventually exhaust its food supply and starve, and so it must be reintroduced should spider mite infestations reoccur.