UC IPM Online UC ANR home page UC IPM home page


SKIP navigation


How to Manage Pests

UC Pest Management Guidelines

Plum rust mites.


Eriophyid Mites

Scientific names:
Plum rust mite: Aculus fockeui
Big-beaked plum mite: Diptacus gigantorhynchus
and others in the genus Eriophyes

(Reviewed 5/06, updated 4/09)

In this Guideline:


Eriophyid mites are tiny, microscopic mites that have two pairs of legs near the anterior end of the body. They are yellow to pinkish white to purplish in color, and wedge-shaped with the widest part of the body being just behind the head.


All species feed on leaves. Heavily infested leaves take on a silvery or bronze appearance, depending on the species. Severe infestations can interfere with photosynthesis, but research indicates that populations as high as 120 eriophyid mites per leaf do not impact yield during the year of infestation.


Eriophyid mites are more likely to reach high densities in sprayed orchards where predaceous mites are destroyed.

Biological Control
Light to moderate populations are suppressed by predaceous mites.

Organically Acceptable Methods
Biological control and sulfur sprays are acceptable for use on organically certified produce.

Treatment Decisions
Treatments are only recommended in orchards with chronic infestations or when there is a danger of defoliation.

Common name Amount to Use** R.E.I.+ P.H.I.+
(trade name) (conc.) (dilute) (hours) (days)

Calculate impact of pesticide on air quality
Bee precaution pesticide ratings
The following materials are listed in order of usefulness in an IPM program, taking into account efficacy, impact on natural enemies and honey bees, and impact of timing on beneficials. When choosing a pesticide, also consider information relating to environmental impact. Not all registered pesticides are listed. Always read label of product being used.
A. WETTABLE SULFUR# Label rates 0 24 0
  MODE OF ACTION: Unknown. An inorganic insecticide.
  COMMENTS: Do not apply within 2 weeks of oil spray.
  (Vendex) 50WP 1–2 lb 0.5 lb 48 14
  COMMENTS: Do not apply more than twice a season.
** 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 the label allows.
+ Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) 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.
# Acceptable for use on organically grown produce.
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 are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Plum
UC ANR Publication 3462
Insects and Mites
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
K. R. Day, UC Cooperative Extension, Tulare County
Acknowledgment for contributions to Insects and Mites:
R. E. Rice, Kearney Agricultural Center, Parlier

Top of page

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2017 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   Contact webmaster.