Adults are pear-shaped, light tan mites, less than 0.5 mm (1/50 inch) long, similar to 'Fallacis' and ‘Cucumeris’ in appearance and life cycle
ORIGIN : California and Florida, occurs in Central America, Mediterranean region
HOST PEST : Spider mites, Pacific mite, Broad mite, Cyclamen mite.
HOST PLANT : Strawberries, Corn, Grapes, Citrus, Roses, Ornamentals
LIFE STAGES : Egg, Larvae, Protonymph, Deutonymph, and Adult
SEX RATIO : Females predominant 4 to 1.
DEVELOPMENT : 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.
ENVIRONMENT : 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. Field tolerance will vary with spray timing, application methods, weather and crop. Avoid spraying crop one week before or after releasing predators. Some materials may be toxic to predators for up to four weeks.
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 5 days, to minimize mortality. They are not canabalistic and survive shipping very well.
AUGMENTATION : Release rates are being developed. Release 1 - 4 per plant or 1 - 2 per square foot in greenhouses at the first sign of spidermites. Use 5,000-10,000 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.
USES : It can reduce numbers of spidermites and then persist on the crop when the pest mites are at very low densities. It works well in interior plantscapes, greenhouses, strawberries, ornamentals and roses. N. californicus tolerates hot dry greenhouse conditions. It has successfully controlled 2-spotted mite on miniature roses at temperatures exceeding 100º F and humidities dropping to 20%. Preliminary studies indicate that N. californicus can successfully control 2-spotted mite in strawberries where P. persimilis was unsuccessful. Recommended release rate on peppers is 1 predator/m 2 (10 ft 2) in infested areas or once flowers are producing pollen.