Agriculture: Apricot Pest Management Guidelines

Brown Mite

  • Bryobia rubrioculus
  • Description of the Pest

    The brown mite can be an economic pest of apricots. It is the largest of all apricot pest mites. Brown mite eggs hatch in early spring and the newly hatched mites are red with six legs. After the first molt they are brown with eight legs and resemble the adult. Adults are flattened with long front legs. The mites feed only during the cool parts of the day, and migrate off the leaves during midday. They are not active during hotter periods of the summer. There are two to three generations per year between February and June.

    Damage

    Brown mite is seldom a pest; feeding causes yellowing of the foliage, but leaves rarely drop. Infestations are generally localized and confined to a few trees.

    Management

    Predators will generally keep brown mite numbers below damaging levels. Allowing low numbers of brown mites in the orchard during spring enables mite predators to increase their numbers to levels that are more effective in controlling webspinning mites. Generally, hot weather and predators cause brown mite numbers to decline in summer.

    Biological Control

    The western predatory mite and brown lacewing are both effective predators, but alone may not control brown mite numbers. Nevertheless, it is important to avoid insecticides that will kill these natural enemies.

    Organically Acceptable Methods

    Use biological control and oil sprays on organically grown apricots.

    Monitoring and Treatment Decisions

    These mites are generally controlled by a dormant spray of oil. Occasionally there may be an infestation during a cool spring when dormant treatments were inadequate.

    Common name Amount to use** REI‡ PHI‡
    (Example trade name) (conc.) (dilute) (hours) (days)
    Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Always read the label of the product being used.
     
    DORMANT
    A. NARROW RANGE OIL# 4–8 gal 1.5–2 gal 12 0
      MODE OF ACTION: Contact including smothering and barrier effects.
      COMMENTS: Cover all parts of the tree. Oil alone will control low to moderate infestations. Do not apply oil to water-stressed trees. Some of the new lower-chilling varieties, especially Poppycot, can be highly susceptible to oil damage. Use extreme care when applying oil to these varieties. Check with certifier to determine which products are organically acceptable.
    ** For concentrate applications, use the amount given in 80 to 100 gal water/acre or lower if the label allows; for dilute application, amount is per 100 gal water to be applied in 300 to 400 gal water/acre, according to label.
    Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.
    # Acceptable for use on organically grown produce.
    Text Updated: 10/14
    Treatment Table Updated: 10/14