Galendromus occidentalis

  • Common Name: Western Predatory Mite
  • Family: Phytoseiidae
  • Genus: Galendromus
  • Species: occidentalis (ox ci den tal us)

ORIGEN: Western North America

HOST PEST: All stages of Spider mites (not effective on eggs of European red mites).

HOST PLANT: Fruit trees, grapes, corn, cotton, ornamentals and strawberries.

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

SEX RATIO: Female predominant usually 2:1 or 3:1

DEVELOPMENT: Egg to Adult: 7 to 14 days depending on temperature.

ENVIRONMENT: Does best in warm weather (80 to 110 F). Tolerates low humidity of inland valleys. Does not do well in cool coastal areas. Goes into diapause (hibernation) in colder temperatures. Recommended for greenhouses only if plants are maintained as low as 30% relative humidity.

PESTICIDES: Some strains tolerate Guthion, Sevin, Sulfur. Developing tolerance to Pyrethroids. Field tolerance will vary with spray timing, application methods, weather and crop. Avoid spraying one week before or after releasing predators. Some materials may be toxic for up to four weeks.

STORAGE: Highly perishable, should be applied to the crop as soon as possible. If storage is necessary refrigerate at 45-50 F. for up to five days.

AUGMENTATION: Release rates on field crops range from 2,000 to 5,000/acre at the first sign of spider mites. In greenhouses, 2/sq ft. or 1 predator per 5 spider mites at the first sign of spider mites. Later releases will require much higher numbers to be effective.

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