Agriculture: Citrus Pest Management Guidelines

Citrus Bud Mite

  • Eriophyes sheldoni
  • Description of the Pest

    Citrus bud mite is very small, elongated and somewhat tapered at the posterior end, and has four legs at the front end near the mouth. Females lay about 50 eggs mostly in the bud scales of recent growth. Mite numbers peak in summer, and summer and fall blooms are most likely to suffer damage.

    Damage

    Citrus bud mite is primarily a pest of coastal lemons but in recent years has also been found in interior regions of Southern California. The mites feed inside the buds, killing them or causing a rosettelike growth of the subsequent foliage and distortion of flowers and fruit, which may or may not reduce yield, fruit quality, or both.

    Management

    Recent research has failed to show any consistent harm caused by bud mite feeding under oil spray regimes, especially in Lisbon lemons, and bud mite damage is offset by the negative phytotoxic effects of oil. Research has not been done to determine if abamectin plus oil sprays for bud mite are economically justified. To detect bud mites before damage occurs:

    1. Check buds on green angular twigs from mid-spring to autumn.
    2. Collect one bud from each of 50 randomly chosen trees throughout the orchard.
    3. Dissect the buds under a microscope or use a 20X hand lens to determine the percent of buds infested with one or more live mites.

    As an alternative to dissecting buds, bud infestation can be estimated from infested fruit buttons.

    1. Collect one green fruit, about 1.25 to 2 inches in diameter, from 50 trees scattered throughout the orchard.
    2. Remove the button and record whether the button or the fruit beneath the button is infested with live bud mites. The relationship between fruit and bud infestations is not linear, but a fruit infestation of 15 to 20% indicates a bud infestation of about 45 to 50%.

    No bud mite threshold had been established; levels as high as 80% bud infestation have failed to cause consistent or predictable economic losses. If a reduction of bud mite numbers is desired, apply insecticides 2 to 3 months before the bloom that is to be protected.

    Common name Amount to use REI‡ PHI‡
    (Example trade name) (type of coverage)** (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.
    A. FENBUTATIN OXIDE
    (Vendex 50WP) 2–4 lb/acre (LV) 48 7
    RANGE OF ACTIVITY: Pests: narrow (mites); Natural enemies: predatory mites
    PERSISTENCE: Pests: short; Natural enemies: short
    MODE-OF-ACTION GROUP NUMBER1: 12B
    . . . PLUS . . .
    NARROW RANGE OIL
    (415, 440) 10 gal/acre (LV) See label When dry
    RANGE OF ACTIVITY: Pests: broad (unprotected stages of insects and mites); Natural enemies: most
    PERSISTENCE: Pests: short; Natural enemies: short
    MODE OF ACTION: Contact including smothering effects.
    COMMENTS: To help prevent development of resistance, alternate with dilute oil sprays. Potential of phytotoxicity to leaves, especially if applied during hot weather. Caution: Serious hazards are associated with oil sprays to green lemons because of phytotoxicity after sweating; check label for preharvest interval.
    B. ABAMECTIN
    (Agri-Mek SC) 2.25–4.25 fl oz/acre (OC or IC) 12 7
    RANGE OF ACTIVITY: Pests: intermediate (citrus thrips, mites, leafminers); Natural enemies: predatory mites and thrips
    PERSISTENCE: Pests: intermediate; Natural enemies: intermediate
    MODE-OF-ACTION GROUP NUMBER1: 6
    . . . PLUS . . .
    NARROW RANGE OIL
    (415) 0.25–1% See label When dry
    RANGE OF ACTIVITY: Pests: broad (unprotected stages of insects and mites); Natural enemies: most
    PERSISTENCE: Pests: short; Natural enemies: short
    MODE OF ACTION: Improves translaminar movement and persistence of insecticide.
    COMMENTS: For use on all varieties. Apply in 500 to 1,000 gal/acre. Certain formulations emit high amounts of volatile organic compounds (VOCs); use low-VOC formulations. Regulations affect use for the San Joaquin Valley from May 1 to October 31, 2020. Review the Department of Pesticide Regulation's updated fact sheet.
     
    C. CYANTRANILIPROLE/ABAMECTIN
      (Minecto Pro) 10-12 fl oz/acre 12 7
      RANGE OF ACTIVITY: Pests: broad (many insects and mites); Natural enemies: predatory mites
      PERSISTENCE: Pests: intermediate; Natural enemies: intermediate
      MODE-OF-ACTION GROUP NUMBER1: 28/6
      ...PLUS...
      415 NARROW RANGE OIL
      (various products) 0.25–1% See label See label
      RANGE OF ACTIVITY: Pests: broad (unprotected stages of insects and mites); Natural enemies: most
      PERSISTENCE: Pests: short; Natural enemies: short
      MODE OF ACTION: Contact including smothering and barrier effects; also improves translaminar movement and insecticide persistence.
      COMMENTS: Do not exceed a total of 24 fl oz of Minecto Pro or 0.40 lbs a.i. of cyantraniliprole-containing products or 0.047 lbs a.i. of abamectin-containing products/acre per calendar year. Do not apply to nurseries. Aerial application is allowed only for citrus leafminer or Asian citrus psyllid. For citrus bud mite, spray at bud swell for best results.
     
    D. NARROW RANGE OIL (UR 92%)
    (415, 440) 1.2–1.4% (TC) See label When dry
    . . . or . . .
    NARROW RANGE OIL (UR 99%)
    (415, 435, 440, 455) 1.2–1.4% (TC) See label When dry
    RANGE OF ACTIVITY: Pests: broad (unprotected stages of insects and mites); Natural enemies: most
    PERSISTENCE: Pests: short; Natural enemies: short
    MODE OF ACTION: Contact including smothering effects.
    COMMENTS: Can apply anytime between March and November. Caution: Serious hazards are associated with oil sprays to green lemons because of phytotoxicity after sweating; check label for preharvest interval.
    E. SPIROTETRAMAT
    (Movento) 8–10 oz/acre 24 1
    RANGE OF ACTIVITY: Pests: broad (mites, thrips, leafminers, aphids, armored scales); Natural enemies: predatory mites
    PERSISTENCE: Pests: intermediate; Natural enemies: short
    MODE-OF-ACTION GROUP NUMBER1: 23
    . . . PLUS . . .
    NARROW RANGE OIL
    (415) 0.5–1% See label See label
    RANGE OF ACTIVITY: Pests: broad (unprotected stages of insects and mites); Natural enemies: most
    PERSISTENCE: Pests: short; Natural enemies: short
    MODE OF ACTION: Contact including smothering effects; also improves insecticide uptake.
    F. FENPYROXIMATE
    (Fujimite SC) 2–4 pt (OC or IC) 12 3
    RANGE OF ACTIVITY: Pests: narrow (mites); Natural enemies: predatory mites
    PERSISTENCE: Pests: intermediate; Natural enemies: intermediate
    MODE-OF-ACTION GROUP NUMBER1: 21A
    ** LV - Low-volume uses 20 to 100 gal/acre.
    OC - Outside coverage uses 100 to 250 gal water/acre.
    IC - Intermediate coverage uses 250 to 600 gal/acre.
    TC - Thorough coverage uses 750 to 2,000 gal water or more/acre, depending on tree size.
    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.
    * Permit required from county agricultural commissioner for purchase or use.
    1 Rotate chemicals 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; chemicals with a 1B group number should be alternated with chemicals that have a group number other than 1B. Mode-of-action group numbers (un = unknown or uncertain mode of action) are assigned by IRAC (Insecticide Resistance Action Committee).
    Text Updated: 02/17
    Treatment Table Updated: 01/19