Description of the Pest
The female European red mite is about 0.02 inch long and has a brick red, globular body with long curved hairs that arise from white spots or tubercles on the back. Nymphs or unfed females may appear greenish. European red mite eggs are red, slightly flattened, and have a stipe protruding from the top. They overwinter in the egg stage on twigs and spurs. Eggs hatch in early spring just after the trees leaf out, and many generations (8–10) are produced before fall. Ordinarily European red mite populations build up slowly during spring and do not become apparent until large populations are present.
Damage
European red mites remove the contents of the leaf cells as they feed, causing leaves to take on a finely mottled appearance. Rarely do European red mites cause leaf drop in nectarine trees.
Management
European red mites provide an early season food source for predatory mites and do little damage unless the orchard is heavily infested. Allowing low populations of European red mites in spring helps build predator mite populations to build, which can later help control the more damaging webspinning mites. Generally treatments for this mite are applied in the dormant to delayed-dormant season.
Biological Control
The same predators that feed on Pacific and twospotted mites will also feed on European red mites. While the western predatory mite can sustain itself on European red mites, it cannot break the shell of European red mite eggs. Thus it takes longer for this predator to bring a population of these mites under control.
Cultural Control
Culturally, little can be done to control European red mites, as it is generally more abundant in well-managed, vigorous orchards.
Organically Acceptable Methods
Biological control and sprays of certain narrow range oil are organically acceptable management tools.
Monitoring and Treatment Decisions
Monitor for European red mite eggs along with other pests when taking the DORMANT SHOOT SAMPLE. Examine leaf scars and growth rings on twigs for the presence of eggs. Use an oil spray during dormancy to help control the overwintering eggs if 20% or more of the shoots have eggs, but remember that low to moderate populations are beneficial because they provide food for predators. During summer, look for stippling or bronzing on leaves. No specific numbers have been developed to initiate treatment for European red mites.
| 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. | |||||
| DORMANT and DELAYED-DORMANT | |||||
| A. | NARROW RANGE OIL# | ||||
| (440 or higher) | 4–6 gal | 1–1.5 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 to control peach twig borer. | |||||
| POSTBLOOM | |||||
| 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; need complete coverage of both leaf surfaces for good control. | |||||
| C. | ABAMECTIN* | ||||
| (Agri-Mek SC) | 2.25–4.25 fl oz | 0.5–1 fl oz | 12 | 21 | |
| MODE-OF-ACTION GROUP NUMBER1: 6 | |||||
| COMMENTS: May be combined with oil. Do not make more than 2 applications per growing season and allow at least 21 days between treatments. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. To avoid illegal residues, see label for required spray additives. | |||||
| D. | FENBUTATIN OXIDE* | ||||
| (Vendex 50WP) | 1–2 lb/acre | 48 | 14 | ||
| MODE-OF-ACTION GROUP NUMBER1: 12B | |||||
| COMMENTS: Can be combined with oil. | |||||
| E. | NARROW RANGE OIL# | ||||
| (Superior, Supreme) | 4 gal | 1–1.5 gal | See label | 0 | |
| MODE OF ACTION: Contact including smothering and barrier effects. | |||||
| COMMENTS: Do not apply during the same season as propargite. Will reduce mite populations by 50%. Multiple applications may be necessary to keep populations below economic levels. | |||||
| F. | CLOFENTEZINE | ||||
| (Apollo) | 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. | |||||
| G. | HEXYTHIAZOX | ||||
| (Onager) | 12–24 oz | 3–6 oz | 12 | 7 | |
| (Savey 50DF) | 3–6 oz | 0.75–1.5 oz | 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 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). |