Agriculture: Nectarine Pest Management Guidelines

Peach Silver Mite

  • Aculus cornutus
  • Description of the Pest

    Peach silver mites are tiny, four-legged eriophyid mites, yellow to pinkish white, and somewhat wedge shaped, being broadest just behind the anterior end. Because they are so tiny, they are difficult to see without a hand lens of at least 10x power.

    Peach silver mites overwinter as females in bark crevices, around buds, and under bud scales. They move to leaves soon after budbreak in spring. These mites can also be found on small fruit, often inhabiting the area between the calyx and the fruit. Later in the season they are found primarily on the lower leaf surface. Before leaf fall, females move to overwintering sites. Many generations are produced during the season.

    Damage

    On rare occasions when very high populations of peach silver mite survive the winter, they produce symptoms on the unfolding leaves. Symptoms consist of minute, yellow spots and a tendency for the leaf edges to curl toward the midrib. Ordinarily, however, most injury is not noticed until mid- to late summer when heavily infested leaves take on a silvery appearance.

    Management

    Treatments applied specifically for control of peach silver mite are rarely needed and should be avoided because peach silver mites serve as early season food for predaceous mites, which in turn aid in reducing populations of other pest mites. The use of broad-spectrum insecticides for other pests can cause high infestations of peach silver mite.

    Organically Acceptable Methods

    Sulfur sprays are acceptable for organically certified crops, but will reduce predator mite populations.

    Monitoring and Treatment Decisions

    If heavy populations (200–300 per leaf) of peach silver mite are present and causing damage, consider applying sulfur or miticides used for control of other mite species. Some insecticides applied for control of other pests eliminate peach silver mites as well.

    Common name Amount per acre** 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 and 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.
     
    A. WETTABLE SULFUR# 5 lb 24 0
      MODE OF ACTION: Unknown. An inorganic miticide.
      COMMENTS: Do not apply within 2 weeks of oil spray. May reduce predator mite populations.
    ** For dilute applications, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for concentrate applications, use 80-100 gal water/acre, or lower if label allows.
    # Acceptable for use on organically grown produce.
    Not recommended or not on 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.
    Text Updated: 06/10
    Treatment Table Updated: 09/15