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How to Manage Pests
UC Pest Management Guidelines
Nectarine
Brown Mite
Scientific Name: Bryobia rubrioculus
(Reviewed 6/06,
updated 6/06)
In this Guideline:
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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.
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 sp), damsel bugs (Nabis sp.), lady
beetles (Hippodamia
convergens and Stethorus
picipes), and minute pirate bug (Orius
tristicolor).
Organically Acceptable
Methods
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** |
P.H.I.+ |
| (trade name) |
(conc.) |
(dilute) |
(days) |
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| 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 the timing on beneficials. When choosing
a pesticide, also consider information relating to environmental impact.
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| DORMANT OR DELAYED DORMANT (Preferred timing)
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| A. |
DORMANT OIL such as:
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DORMANT FLOWABLE EMULSION |
6–8 gal |
1.5–2 gal |
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NARROW RANGE OIL# |
6 gal |
1.5 gal |
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MODE OF ACTION: Contact including smothering and barrier effects. |
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COMMENTS:
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. |
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| SPRING AND SUMMER |
| A. |
FENBUTATIN OXIDE*
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(Vendex) 50WP |
2 lb |
0.5 lb |
14 |
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MODE OF ACTION: Unknown. An organotin miticide. |
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COMMENTS:
This material appears to be most effective when applied earlier in the season
rather than later. Can be combined with oil. Do not apply more than twice a season in not more than 400 gal water/acre. |
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| B. |
NARROW RANGE OIL# |
2% |
4% |
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MODE OF ACTION: Contact including smothering and barrier effects. |
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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. |
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UC IPM Pest Management Guidelines: Nectarine
UC ANR Publication 3451
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 the insects and mites section:
R. E. Rice, Kearney Agricultural Center, Parlier
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