Description of the Pest
Brown mites can be recognized by their flattened bodies and long front legs. Adults are brownish green; nymphs are red at first. Brown mites overwinter as eggs on spurs and branches. Eggs are red and similar in appearance to European red mite eggs but lack a stipe. Eggs hatch in spring and the young move out to leaves where they feed but do not produce webbing. Brown mites feed only during the cool parts of the day and migrate off the leaves during midday.
Damage
Brown mites feed by sucking the contents out of leaf cells. Such leaf damage reduces tree vitality and can adversely affect fruit size. Leaf injury caused by brown mites begins as a mottling and browning of leaves. Trees can tolerate low to moderate populations of brown mite, but heavy populations can remove almost all the chlorophyll from leaves and entire trees will take on a pale yellow appearance.
Management
Maintain mite predators in order to keep brown mite populations at low levels.
Biological Control
Several predaceous species feed on brown mite, including lacewings (Chrysoperla spp., Chrysopa spp., and Hemerobius spp.), damsel bugs (Nabis sp.), lady beetles (Hippodamia convergens and Stethorus picipes), and minute pirate bug (Orius tristicolor).
Organically Acceptable Methods
Certain oil sprays and naturally occurring predators serve as organically acceptable management tools.
Monitoring and Treatment Decisions
Monitor for brown mite eggs along with other pests when taking the DORMANT SHOOT SAMPLE. Use dormant sprays with oils at the high rate to help control the overwintering eggs if 20% or more of the shoots have eggs. An insecticide can be added to control other pests. Miticides may be necessary in some orchards in spring or summer but only when mite populations begin damaging foliage. During the hot part of the day, brown mites will not be found on leaves, but they can be monitored using beating trays. Allowing low populations of brown mites in the orchard during spring enables mite predators to increase their population to levels that are more effective in controlling webspinning mites. Generally, hot weather and predators cause brown mite populations to decline in summer.
| 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 or DELAYED-DORMANT (Preferred timing) | |||||
| A. | DORMANT OIL such as: | ||||
| DORMANT FLOWABLE EMULSION | 6 gal | 1.5–2 gal | 12 | 0 | |
| NARROW RANGE OIL (440 or higher)# | 6 gal | 1.5 gal | 12 | 0 | |
| MODE OF ACTION: Contact including smothering and barrier effects. | |||||
| COMMENTS: Choose a narrow range oil with a 50% distillation point of 440 or higher for dormant season use. Always check with your certifier as to which oils are organically acceptable. With good coverage, oil will control European red mite and brown mite eggs and low infestations of San Jose scale. Use in conjunction with a bloom time spray of Bt to control peach twig borer. | |||||
| SPRING AND SUMMER | |||||
| A. | BIFENAZATE | ||||
| (Acramite 50WS) | 0.75–1 lb/acre | 12 | 3 | ||
| MODE-OF-ACTION GROUP NUMBER1: un | |||||
| COMMENTS: Relatively safe for beneficial predaceous mites. Apply with ground equipment. Requires complete coverage of both leaf surfaces for effective control. Toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | |||||
| B. | SPIRODICLOFEN | ||||
| (Envidor 2SC) | 16–18 fl oz/acre | 12 | 7 | ||
| MODE-OF-ACTION GROUP NUMBER1: 23 | |||||
| COMMENTS: Apply with ground equipment. Requires complete coverage of both leaf surfaces for effective control. | |||||
| C. | FENBUTATIN OXIDE* | ||||
| (Vendex 50WP) | 1–2 lb/acre | 48 | 14 | ||
| MODE-OF-ACTION GROUP NUMBER1: 12B | |||||
| COMMENTS: Can be combined with oil. | |||||
| D. | NARROW RANGE OIL# | 2% | 4% | 12 | 0 |
| MODE OF ACTION: Contact including smothering and barrier effects. | |||||
| COMMENTS: Oil used alone will only provide partial control. Always apply oils to well-watered trees and never when trees are stressed by hot (above 90°F), windy, dry (relative humidity lower than 20%) conditions or when such conditions are likely to occur within a few days after application. Additional applications may be needed at 2-week intervals, which may increase the potential for phytotoxicity. Do not apply oil within 2 weeks of captan or sulfur. | |||||
| E. | CLOFENTEZINE | ||||
| (Apollo SC) | 2–8 oz/acre | 12 | 10 | ||
| MODE-OF-ACTION GROUP NUMBER1: 10A | |||||
| COMMENTS: Kills eggs and young larval stages so it is best suited for an early season application if needed. Use rates below 4 oz/acre only when adequate numbers of predators are present. Good coverage is a must; use a minimum of 50 gal water/acre for concentrate sprays and a maximum of 400 gal water/acre for dilute. To delay development of resistance, use only once per season. | |||||
| F. | HEXYTHIAZOX | ||||
| (Onager) | 12–24 oz/acre | 12 | 7 | ||
| (Savey 50DF) | 3–6 oz/acre | 12 | 28 | ||
| MODE-OF-ACTION GROUP NUMBER1: 10A | |||||
| COMMENTS: Apply after bloom but before adult mite buildup. Controls eggs and immatures that are sprayed or move onto treated surfaces; does not kill adult mites but will kill eggs laid on treated surfaces. Do not make more than 1 application per year. | |||||
| ** | 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. | ||||
| * | 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 two intervals is the minimum time that must elapse before harvest. | ||||
| # | 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 ("un" = unknown or uncertain mode of action) are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/. | ||||