Description of the Pest
European red mites overwinter as eggs; eggs hatch in spring when trees bloom. With the use of a hand lens, look for overwintering eggs in roughened bark at bases of buds and spurs on smaller branches and twigs, or in wounds. They are globular and red with a slender stalk (stipe) rising from the top center and many grooves extending from top to bottom. During the growing season, eggs are laid on leaves. There are three instars before the adult stage. Immature mites are bright red, except just after molting when they appear bright green. The green color turns to red after the mites resume feeding. Adults are dark red and have six to eight white spots at the base of hairs on the back.
Damage
Severe mite infestations can cause bronzing of leaves. Damage is relatively less severe on wide leaf varieties such as Yellow Newton and more severe on narrow leaf varieties such as Red Delicious.
Management
European red mite only occasionally becomes troublesome in apple orchards. Monitor in winter to determine the need for treatment. Dormant oil is the preferred treatment.
Biological Control
If European red mite populations are managed at low levels by treating with a dormant oil, predators including western predatory mite, sixspotted thrips and spider mite destroyer can effectively help to maintain low levels throughout the season. Minimize the use or dosages of materials disruptive to mite predators. Avoid spraying with materials such as lime sulfur which kill the apple rust mite. When apple rust mites are allowed to survive, the predaceous mites feed on them and can build up large enough populations to control European red mites in some areas of California.
Cultural Control
Minimize the potential for mite problems by reducing dusty conditions within the orchard and keeping the trees well irrigated.
Organically Acceptable Methods
Biological and cultural controls and sprays of approved narrow range oils are organically acceptable.
Monitoring and Treatment Decisions
Anytime during winter collect 25 to 100 fruit spurs from trees throughout the block. If less than 10% of the spurs are infested, European red mite probably will not become a problem that season. If more than 10% of the spurs are infested, an oil spray should be applied before bloom. Control improves the closer eggs are to hatching. If summer control becomes necessary, the thresholds range from 10 to 30 mites per leaf depending on the age, variety, and condition of the tree, and the abundance of the mite predators.
| 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, 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. | |||||
| DELAYED DORMANT (Preferred timing) | |||||
| A. | NARROW RANGE OIL# | 6 gal | 1.5 gal | See label | 0 |
| MODE OF ACTION: Contact including smothering and barrier effects. | |||||
| COMMENTS: Check with certifier to determine which products are organically acceptable. | |||||
| FOLIAGE SPRAY – PETAL FALL TO HARVEST | |||||
| A. | NARROW RANGE OIL | 4 gal | 1 gal | 4 | 0 |
| MODE-OF-ACTION: Contact including smothering and barrier effects. | |||||
| . . . PLUS . . . | |||||
| ABAMECTIN* | |||||
| (Agri-mek SC) | Label rates | 12 | 28 | ||
| MODE-OF-ACTION GROUP NUMBER1: 6 | |||||
| COMMENTS: Narrow-spectrum preventive material that can be applied early in the season (from petal fall to 6 weeks later) when mite outbreaks are anticipated. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. Certain abamectin formulations emit high amounts of volatile organic compounds (VOCs); use low VOC formulations of abamectin. | |||||
| B. | PYRIDABEN | ||||
| (Nexter) | 4.4–5.2 oz | 12 | 25 | ||
| MODE-OF-ACTION GROUP NUMBER1: 21A | |||||
| COMMENTS: Can be used later in the season than preceding materials. Do not use less than 100 gal water/acre spray volume. Most effective with use of a silicone spreader. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | |||||
| C. | ACEQUINOCYL | ||||
| (Kanemite 15 SC) | 21–31 fl oz | 12 | 14 | ||
| MODE-OF-ACTION GROUP NUMBER1: 20B | |||||
| COMMENTS: Harmless to predatory mites. | |||||
| D. | SPIRODICLOFEN | ||||
| (Envidor 2 SC) | 16–18 fl oz | 12 | 7 | ||
| MODE-OF-ACTION GROUP NUMBER1: 23 | |||||
| COMMENTS: Slightly harmful to predatory mites. | |||||
| E. | HEXYTHIAZOX | ||||
| (Savey 50 DF) | 3–6 oz | 12 | 28 | ||
| (Onager) | 12–24 oz | 12 | 28 | ||
| MODE-OF-ACTION GROUP NUMBER1: 10A | |||||
| COMMENTS: Kills eggs. Need to apply early, before monitoring indicates a need; use in orchards where European red mite is a chronic pest. Apply only once per growing season. | |||||
| F. | FENPYROXIMATE | ||||
| (FujiMite 5EC) | 2 pt | 12 | 14 | ||
| MODE-OF-ACTION GROUP NUMBER1: 21A | |||||
| COMMENTS: Harmful to predatory mites. Most effective with use of a silicone spreader. | |||||
| G. | ETOXAZOLE | ||||
| (Zeal) | 2–3 oz | 12 | 14 | ||
| MODE-OF-ACTION GROUP NUMBER1: 10B | |||||
| COMMENTS: Harmful to predatory mites; preliminary research indicates etoxazole has an effect on the reproductive capacity of predatory mites. Most effective with use of a silicone spreader. | |||||
| H. | BIFENAZATE | ||||
| (Acramite 50WS) | 0.75–1 lb | 12 | 7 | ||
| MODE-OF-ACTION GROUP NUMBER1: 20D | |||||
| COMMENTS: Harmless to predatory mites. Only one application per crop per year. Most effective with use of a silicone spreader. | |||||
| I. | CLOFENTEZINE | ||||
| (Apollo SC) | 4–8 oz | 12 | 45 | ||
| MODE-OF-ACTION GROUP NUMBER1: 10A | |||||
| COMMENTS: For early and mid-season mite control; easy on natural enemies. Kills eggs. Need to apply early, before monitoring indicates a need; use in orchards where European red mite is a chronic pest. 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. | |||||
| ** | For dilute application, rate is per 100 gal water to be applied in 300 to 500 gal water/acre, according to label; for concentrate applications, use 80 to 100 gal water/acre or lower if the label allows. |
| ‡ | 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. |
| # | 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). |