Neoseiulus californicus

  • COMMON NAME: Californicus
  • FAMILY: Phytoseiidae
  • GENUS: Neoseiulus (formerly: Amblyseius)
  • SPECIES: californicus

ORIGIN: California and Florida

HOST PEST: Spider mites, Broad mite, Cyclamen mite.

HOST PLANT: Strawberries, Corn, Grapes, Roses, Vegetables, Ornamentals

LIFE STAGES: Egg, Larvae, Protonymph, Deutonymph, and Adult

SEX RATIO: Females predominant 2 to 1.

DEVELOPMENT: Completes a generation in one to two weeks depending on temperature.

ENVIRONMENT: Does best in warm humid conditions, but will also tolerate low humidity (40% - 80%rh at 50° - 105°F). Occurs naturally along coast and inland valleys of California, Florida, Chile and around the Mediterranian Sea.


AUGMENTATION: Californicus is a very versatile predator. It tolerates a wider range of temperatures and lower humidities than P. persimilis. It is being used on a wide variety of plants including; strawberries, raspberries, roses, grapes, ornamentals and vegetables. Typical release rates are 1/sq ft., 20-40,000/acre, 100,000/ha. Rates are dependent upon pest levels and desired speed of control. Recommended pest/predator ratio at time of release is 10/1. Avoid releases in temperatures below 45° F. or above 85° F and during dry windy conditions. It is preferable to release predators in the morning while humidities are high and the soil is not hot. It is extremely important to release predators as soon as pest mites appear in the crop.

PESTICIDES: Susceptible to many pesticides. Field tolerance will vary with type of spray, timing, application methods, weather and crop. Avoid spraying crop one week before or after releasing predators. Some pesticides may remain toxic to predators for up to four weeks.

STORAGE: Highly perishable, should be released immediately upon delivery. If storage is absolutely necessary, refrigerate at 55ºF. (12ºC). Not to exceed 5 days, to minimize mortality.

BIOLOGY: The following data are based on a temperature of 25ºC (77ºF).
Egg: The egg is oval and much larger than spider mite eggs. Hatch in 2 days.
Larval: Non feeding stage, 1/2 day.
Protonymph: First feeding stage, 1 1/2 days.
Deutonumph: Second feeding stage, 1 day.
Egg to adult: five days.
Preoviposition period: 1 1/2 days.
Average temperatures higher than 77ºF. will speed up reproduction. Temperatures lower than 77ºF will slow down reproduction. Reproduction stops at about 55ºF. Reproduction continues up to 95ºF and survival has been noted at 110 degrees F. At 77ºF the females consumed 5.3 spider mite eggs per day.
At 77ºF the females laid 3.1 eggs/day and laid 43 eggs during lifetime.
During the ovipositional period the females consumed 16.3 eggs per day for about 13.4 days. The intrinsic rate of increase (rm) is 0.29. This means that at this temperature the predator population can increase at the rate of 29%/day under favorable conditions. There is some evidence that californicus can survive on pollen but not reproduce.

Most of this data is from a publication by; Wei-Lan Ma and J.E. Laing, Biology -- of Amblyseius (Neoseiulus)californicus, Entomophaga, 1973, 47-60.


Biotactics Homepage