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How to Manage Pests
UC Pest Management Guidelines
Peach
Fruittree Leafroller
Scientific name: Archips argyrospila
(Reviewed 3/06,
updated 3/06)
In this Guideline:
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DESCRIPTION OF THE PEST
Adult fruittree
leafroller moths are about 0.5 inch long, with rusty brown wings marked with
areas of white and gold. When at rest the adults show the typical bell-shaped
pattern common to the family Tortricidae. The eggs are
laid in masses on limbs and twigs and are covered with a gray secretion that
turns white upon aging. Larvae are
green with a black head. The intensity of the green color varies from a light
green in young larvae to a darker green as they mature. Fruittree leafroller
larvae are difficult to distinguish from the more damaging obliquebanded
leafroller larvae.
The fruittree leafroller
overwinters in the egg stage. Eggs usually hatch in early spring. Larvae feed
within opening buds. As they mature they tie leaves together and feed on
leaves, blossoms, and small fruit. Adults emerge in May or June. These adults
then lay egg masses that overwinter. There is one generation per year.
DAMAGE
Fruittree leafroller damage consists of feeding on blossoms as well
as leaves and developing fruit. Rarely are populations heavy enough to cause a
reduction in the crop, but this pest can leave unsightly surface feeding scars
on the fruit that increase in size as the fruit enlarges, causing it to be
culled before packing.
Delayed dormant treatments and bloom time applications for other
pests help keep leafroller populations under control. However, regular
monitoring each season is important so that prompt action can be taken if
damaging populations develop. In spring, watch for the presence of fruittree
leafrollers while monitoring for other pests. This is especially important in
orchards where bloom time sprays and pheromone confusion are used to control
peach twig borer and oriental fruit moth.
Biological Control
A number of parasites, including species of Macrocentrus, Apanteles,
and Exochus, attack leafroller larvae. General predators such as lacewings,
assassin bugs,
and minute pirate
bugs may feed on eggs and larvae. Preservation of natural enemy populations is an
important part of keeping leafroller numbers low. Use selective materials that
are least disruptive of biological control when treating other pests.
Organically Acceptable Methods
Fruittree leafroller can be managed organically with oil sprays during
the dormant season followed by bloom treatments of Bacillus thuringiensis or the Entrust formulation of spinosad. These treatments are also used to
manage other leafrollers and peach twig borer.
Monitoring and Treatment Decisions
Although a separate treatment for fruittree leafroller control is
seldom needed, inspect orchards during the dormant period for unusually large
numbers of egg masses. Egg masses are about the size of a thumbprint and laid
on smooth wood. Also check flowers during bloom for the presence of the
fruittree leafroller and other larvae (see EARLY SEASON
MONITORING for details). If
damaging populations are observed, a number of environmentally friendly
chemicals are effective in controlling this pest, including Bacillus
thuringiensis, spinosad (Entrust, Success), and methoxyfenozide
(Intrepid).
Take a fruit damage
sample at harvest to assess the effectiveness of the current year's IPM program
and to determine the needs of next year's program. For procedures, see
FRUIT EVALUATION AT HARVEST
and record results on a monitoring
form .
| Common name |
Amount/Acre** |
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 |
| A. |
NARROW RANGE OIL# |
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(Superior, Supreme) |
4–6 gal |
1–1.5 gal |
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MODE OF ACTION: Contact including smothering and barrier effects. |
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COMMENTS:
Oil used alone will provide only partial control. Best when followed by an
application of Bacillus thuringiensis or other environmentally sound insecticides at bloom. |
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| B. |
NARROW RANGE OIL
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(Superior, Supreme) |
4–6 gal |
1–1.5 gal |
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MODE OF ACTION: Contact including smothering and barrier effects. |
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. . PLUS . . .
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DIFLUBENZURON* |
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(Dimilin) 2L |
12 oz |
3 oz |
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MODE OF ACTION: An
insect growth regulator/benzoylurea (Group 15)1 insecticide.
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COMMENTS: Apply in
sufficient water to ensure good coverage. Apply with narrow range oil at 1.5% oil by volume. |
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. . OR . . .
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SPINOSAD |
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(Entrust)# |
1.25–2.5 oz |
0.3–0.6 oz |
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(Success) |
4–8 oz |
1–2 oz |
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MODE
OF ACTION: A microbial (Group 5)1 insecticide.
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| BLOOM |
| A. |
BACILLUS THURINGIENSIS ssp. KURSTAKI#
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(various products) |
Label rates |
— |
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MODE OF ACTION: A
microbial (Group 11.B2)1 insecticide.
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COMMENTS:
Make two applications during bloom: the first between popcorn and the beginning of
bloom and the second 7–10 days later, but no later than petal fall. Compatible with
fungicide sprays, and can be tank mixed with them. Good coverage is
essential. Ground application using a concentrate rate (80–100 gal water
maximum) is preferred. If aerial applications must be made because conditions
do not permit ground application, a concentrate rate (5 gal or less) is
preferred. Fly material on at a height of about 20 ft over the canopy using
appropriate nozzles to allow better deposition on the tree tops. Precede this
treatment with an oil spray during the delayed dormant season to control San Jose scale and European red mite eggs. |
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| B. |
SPINOSAD |
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(Entrust)# |
1.71–2.5 oz |
0.43–0.6 oz |
14 |
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(Success) |
6–8 oz |
1.5–2 oz |
14 |
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MODE
OF ACTION: A microbial (Group 5)1 insecticide.
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COMMENTS: Most
affective when applied at petal fall. This product is toxic to bees for 3
hours following treatment; apply in the late evening after bees have stopped
foraging. Do not apply more than 29 oz/acre/year of Success or 9 oz/acre/year of Entrust. |
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| C. |
METHOXYFENOZIDE |
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(Intrepid) 2F |
8–16 oz |
2–4 oz |
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MODE OF ACTION: An
insect growth regulator (Group 18)1 insecticide.
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COMMENTS: Apply at
petal fall. Do not apply more than 16 fl oz/acre/application or 64 fl oz/acre/season. |
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UC IPM Pest Management Guidelines: Peach
UC ANR Publication 3454
Insects and Mites
C. Pickel, UC IPM Program, Sutter/Yuba counties
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
J. K. Hasey, UC Cooperative Extension, Sutter/Yuba counties
K. R. Day, UC Cooperative Extension, Tulare Co.
Acknowledgment for contributions to the insects and mites section:
R. E. Rice, Kearney Agricultural Center, Parlier
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