|
|
How to Manage Pests
UC Pest Management Guidelines
Almond
Oriental
Fruit Moth
Scientific name: Grapholita
molesta
(Reviewed 3/09,
updated 3/09)
In this Guideline:
|
|
|
Oriental fruit moth is an occasional pest of almonds. It overwinters
as a mature larva in bark cracks and in leaf litter. The small, brown moths emerge in late
February. Larvae are white to pink with a brown head capsule. There are five to
six generations per year.
First and second generation larvae mine young, tender shoots,
causing them to wilt and die. Third and fourth generation larvae feed between
the hull and shell; this damage is difficult to distinguish from that caused by
peach twig borer. Damage is rarely significant. Occasionally, larvae have been
found feeding on nut
meats.
They may feed in groups of several larvae within a nut. Larvae do not produce
webbing but do produce a characteristic reddish brown frass in the hull.
MANAGEMENT Degree-day
calculator Degree-day
table
Oriental fruit moth rarely causes significant damage to almonds.
Sprays are usually only required if significant damage by this pest occurred
the previous year or in orchards that are near to other sources of Oriental
fruit moth (e.g. infested peach and nectarine orchards, which are harvested
before almonds). Monitor Oriental fruit moth densities in late April to early
May by opening shoot
strikes and looking for
larvae, as described in the monitoring section for
peach twig borer. A harvest
sample will help evaluate
the effectiveness of your management program.
Monitoring and Treatment Decisions
Adult Oriental fruit
moth populations can be monitored and treatments timed (if necessary) with pheromone traps. They should be
placed in orchards by February 15 in the northern or eastern quadrant of the
tree, 6 to 7 feet high. Use three traps per orchard or varietal block less than
30 acres. Use one trap per 10 acres for 30- to 80-acre orchards and one trap
per 20 acres for orchards larger than 80 acres. Monitor traps once a week.
Replace pheromone lures according to manufacturer's directions and trap liners
when dirty, or after counting and removing an accumulated total of 150 moths.
Oriental fruit moth traps usually catch many more moths than do peach twig
borer traps, and like peach twig borer traps, trap catch numbers are generally
not a good indicator of potential damage.
To
determine optimum time to spray, accumulate degree-days beginning with the
first male moth trapped from the second flight, which usually occurs in May.
Use a lower threshold of 45°F and an upper threshold of 90°F. (For assistance
in calculating degree-days, see "Degree-days". The optimum time to treat for Oriental fruit moth is
500 to 600 degree-days after first trapped male in any flight.
| Common name |
Amount/Acre** |
R.E.I.+ |
P.H.I.+ |
| (trade name) |
(conc.) |
(dilute) |
(hours) |
(days) |
|
| The following materials are listed in order of usefulness in an IPM program,taking into account efficacy and impact on
natural enemies and honey bees When choosing a pesticide, also consider
information relating to environmental impact. Not all registered pesticides are listed. Always read label of product being used. |
| |
| A. |
SPINETORAM |
| |
(Delegate) WG |
3–7 oz |
0.75–1.75 oz |
4 |
14 |
| |
MODE
OF ACTION GROUP NUMBER1: 5 |
| |
| B. |
CHLORPYRIFOS* |
| |
(Lorsban) 4E |
2 qt |
— |
24 |
14 |
| |
MODE
OF ACTION GROUP NUMBER1: 1B |
| |
COMMENTS:
Do not apply more than 3 foliar applications/season. Do not allow livestock
to graze in treated orchards. Avoid drift or tailwater runoff into surface waters. |
| |
| C. |
AZINPHOSMETHYL* |
| |
(Guthion) 50WP |
2–4 lb |
0.5–1 lb |
30 days |
30 |
| |
MODE
OF ACTION GROUP NUMBER1: 1B |
| |
COMMENTS:
Do not apply more than twice during postbloom. Allow 30 days between applications. |
| |
| D. |
PHOSMET |
| |
(Imidan) 70WP |
4–5 lb |
1 lb |
3 days |
30 |
| |
MODE OF ACTION GROUP NUMBER1: 1B |
| |
COMMENTS:
Do not apply more than 1 foliar spray/season. Breaks down rapidly in water. Can be used where label restrictions prevent use of other organophosphates. |
| |
| E. |
CARBARYL* |
| |
(Sevin) 80S |
5 lb |
1.25 lb |
12 |
14 |
| |
MODE
OF ACTION GROUP NUMBER1: 1A |
| |
COMMENTS:
Do not use early in season or exceed 18.75 lb/acre/season. May cause severe
mite outbreaks. If pest mites are present, add a miticide to the treatment if
carbaryl/organophospate resistant strains of the western predatory mite are not established. |
| |
| F. |
SPINOSAD |
| |
(Entrust)# |
1.25–3 oz |
0.3–0.75 oz |
4 |
14 |
| |
(Success) |
4–10 oz |
1–2.5 oz |
4 |
14 |
| |
MODE
OF ACTION GROUP NUMBER1: 5 |
| |
COMMENTS: Apply in early morning or evening when bees are not actively foraging. |
| |
IMPORTANT LINKS
UC IPM Pest Management Guidelines: Almond
UC ANR Publication 3431
Insects and Mites
F. G. Zalom, Entomology, UC Davis
C. Pickel, UC IPM Program, UC Cooperative Extension, Sutter/Yuba counties
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
D. R. Haviland, UC IPM Program, UC Cooperative Extension, Kern County
R. A. Van Steenwyk, Insect Biology, UC Berkeley
Acknowledgment for contributions to Insects and Mites:
R. E. Rice, Kearney Agricultural Center, Parlier
L. C. Hendricks, UC Cooperative Extension, Merced County
R. L. Coviello, UC Cooperative Extension, Fresno County
M. W. Freeman, UC Cooperative Extension, Fresno County
Top of page
|