Agriculture: Almond Pest Management Guidelines

Peach Silver Mite

  • Aculus cornutus
  • Description of the Pest

    Peach silver mite is white or cream-colored and extremely small. The body is teardrop-shaped with four short legs at the larger (anterior) end. Because it is much smaller than other mites on almonds, a high-power hand lens (15X or higher) is needed to see it clearly.


    Peach silver mite is not usually damaging in almonds, although it can cause symptoms if numbers increase to high levels on trees less than 6 years old. Feeding by peach silver mite causes tiny chlorotic spots that give the leaf a silvery appearance, especially along the midvein of the upper leaf surface. Symptoms resemble thrips or leafhopper damage. Once higher temperatures occur in late spring, brown necrotic spots develop along leaf margins following silver mite feeding early in the season that may superficially resemble rust symptoms.


    For the most part, peach silver mite is usually considered beneficial to have in the orchard because it serves as a food source for mite predators. Unless peach silver mite numbers are high enough (hundreds to thousands per leaf) that some defoliation is observed, no treatment is necessary.

    Common name Amount per acre REI‡ PHI‡
    (Example trade name) (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.
    (Omni Supreme and others) Label rates See label See label
    MODE OF ACTION: Contact including smothering and barrier effects.
    COMMENTS: Cover all parts of the tree. Will control low-to-moderate infestations. See DORMANT TREATMENT DECISION TABLE for rate to use based on the percent infested spurs. Check with certifier to determine which products are organically acceptable.
    (various products) Label rates 24 0
    MODE OF ACTION: Unknown. An inorganic insecticide.
    COMMENTS: Check with your certifier to determine which products are organically acceptable.
    (Agri-Mek SC, others) Label rates See label See label
    COMMENTS: Apply with 1 to 2% horticultural oil by volume according to label directions. Certain formulations emit high amounts of volatile organic compounds (VOCs); use low-VOC formulations. Regulations affect use for the San Joaquin Valleyfrom May 1 to October 31, 2018 and 2019. Review the Department of Pesticide Regulation's updated fact sheet.
    * Permit required from county agricultural commissioner for purchase or use.
    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 these two intervals is the minimum time that must elapse before harvest may occur.
    # Acceptable for use on organically grown produce.
    1 Rotate pesticides with a different mode-of-action group number, and do not use products with the same mode-of-action group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a group number of 1B; pesticides with a 1B group number should be alternated with pesticides that have a group number other than 1B. Mode-of-action group numbers are assigned by IRAC (Insecticide Resistance Action Committee).
    Text Updated: 08/17
    Treatment Table Updated: 08/17