|
|
How to Manage Pests
UC Pest Management Guidelines
Walnut
Codling Moth
Scientific Name: Cydia pomonella
(Reviewed 12/07,
updated 3/11,
corrected 8/11)
In this Guideline:
|
|
|
Codling moths overwinter as full-grown larvae in thick, silken cocoons under loose scales of bark or in trash on
the ground near the trunk. Moth emergence usually coincides with the leafing
out of early walnut cultivars. During the day, moths rest on branches and
trunks. Codling moths can be distinguished from other small moths
likely to occur in the orchard by the coppery markings on their wing tips.
The
first flight of codling moth typically starts sometime from early March to
early April and is from the overwintered generation. The flight of the
overwintered generation may have two peaks (often referred to as 1A and 1B) and
can last several months. These moths lay eggs that signal the beginning of the
first generation. The second flight of moths results when the larvae of the
first generation complete their development. When the moths in the second
flight lay their eggs, this starts the second generation. The following table
outlines the life history of codling moth:
| Generation |
Resulting moth flight |
Lay eggs for |
| overwintered |
first |
first generation |
| first |
second |
second generation |
| second |
third |
third generation |
| third |
fourth* |
|
| * Only
occurs in warm growing locations
|
Each
overwintered female deposits about 30 eggs singly on leaves near nuts. Later
generations of females will lay an average 60 eggs on leaves or nuts. Eggs are
disc shaped and opaque white. Eggs of the overwintered generation hatch after 5
to 20 days, depending on the temperature, and young
larvae
bore into nutlets through the blossom end. Most nuts with codling moth damage
from the overwintered generation drop to the ground along with blighted nuts.
However, if damage occurs from second flight peak (1B) of overwintered codling
moths and the weather is cool, all damaged nuts do not drop. So only use nut
drop thresholds when there is no second peak in the flight of the overwintered
generation.
Codling
moth egg hatch period is dependent on temperatures but typically the egg hatch
period for the overwintered generation lasts 4 to 6 weeks and 4 weeks for later
generations. (The egg hatch period is important for timing sprays.) In cool
springs or cool locations, the flight of the overwintering generation lasts
longer than subsequent flights and has two peaks.
The
larvae leave the nut after completing their development and pupate under loose bark on the tree. Adults of the
first generation begin to emerge from the end of May to as late as the last
week of June in the Central Valley, depending on the season. In coastal areas,
emergence begins in late June to early July. Because of the higher
temperatures, eggs and larvae of the first generation develop faster than those
laid by the overwintered generation.
Newly
hatched second generation larvae bore into walnuts anywhere on their surfaces
but prefer the spot where two nuts touch. If the nut has hardened, it may take
them up to a week to enter the nut. The larvae develop into adults that begin
to emerge by late July or the beginning of August. In most valley locations
they produce a third generation; in warmer locations a partial fourth generation
may be produced in September. These later generations can cause significant
damage. The larvae leave the nuts when they are fully grown and move to tree
trunks or debris to spin cocoons and overwinter. Occasionally some may be present
in nuts if they are harvested before the larvae have matured. However, most
larvae found in nuts at harvest are navel orangeworm.
It
is important to distinguish between codling moth and navel orangeworm damage.
At harvest it is easy to tell codling moth damage from navel orangeworm damage
when the worms are present. Navel orangeworm has a brown crescent-shaped
marking behind the head capsule on both sides of the first thoracic segment;
this mark is absent in codling moth larvae. If the worm is not present, look at
the damage: navel orangeworm leaves behind more webbing and frass. However,
navel orangeworm frequently infest nuts that were previously infested by
codling moth so if navel orangeworm is present, it doesn't mean codling moth
wasn't previously there.
The damage caused by the codling moth is different with each generation.
First generation larvae reduce yield directly by causing nutlets to drop from
the tree. Codling moth damaged nutlets have frass at the blossom
end. Be
careful not to confuse nuts damaged by codling moths with unpollinated nutlets
or with blight-infected nutlets, which have dark lesions but no frass and drop
at the same time. Damage is generally most severe on early season cultivars,
although it has been increasing steadily over the years on late season
cultivars such as Chandler.
Nuts attacked by larvae from the last part of the first
generation and from the second and third generations remain on the trees but
are unmarketable because of the feeding damage to the kernel. These damaged
nuts can also serve as a breeding site for the navel orangeworm. Feeding that
is confined to the husk results in minor shell staining but no damage to the
kernel.
You can often detect codling moth infestations by looking for
frass produced by the larvae at the point of entry into the husk. Second
generation larvae often enter through the side of the husk where the two nuts
touch. After the shell hardens, the larvae enter the nuts through the soft
tissue at the stem end.
Management options for codling moth in walnut orchards include both
pheromone mating disruption and insecticide sprays. The options that work best
for a given orchard depend on the size of the trees and the degree of codling
moth infestation. In all cases, a program of monitoring with pheromone (codlemone)
and/or pheromone+kairomone (known as CM-DA combo) and checking for damage is
necessary to follow codling moth generations and assess the degree of
infestation and effectiveness of control actions. Programs that use mating
disruption alone or in combination with sprays of least toxic insecticides or
parasite releases pose fewer water quality and environmental risks than
programs that rely on organophosphate or pyrethroid insecticides.
Biological Control
Alone, natural enemies are not able to keep codling moth populations below
economic levels. In orchards where mating disruptants are used, augmentative
releases of the tiny, naturally occurring parasitic wasp, Trichogramma platneri, which attacks codling moth eggs, can be
helpful to control eggs laid by mated female moths immigrating into the area
from surrounding areas but may not be economically feasible. They are most
effective when the orchard's codling moth population is low.
Organically Acceptable Methods
Use of pheromone puffers, hand-applied mating disruption products, and
organically approved insecticides are acceptable for use in organically
certified crops. Sprayable pheromones are not currently approved for
organically certified orchards. While certain oil products are organically
certified and will supply 30-40% egg kill, there is a concern with
phytotoxicity with oils, especially when weather is hot, and oils have been
shown to kill the walnut aphid parasite, Trioxys
pallidus. Always check with your organic certifier to determine what products
are approved for organic certification.
Establishing Biofix and
Accumulation of Degree-Days
In early March, place traps in your orchards to determine first
moth emergence. If using 1 mg (1X) lure traps, put traps in the southeast
quadrant of the tree about 6 to 7 feet high. Traps placed higher in the tree
canopy catch more moths, which may be useful in orchards with low codling moth
populations. Traps with CM-DA lures should be hung mid-canopy and are most
useful in orchards that are either using mating disruption or near other
orchards using mating disruption.
Biofix is the first
date that moths are consistently found in traps and sunset temperatures have
reached 62°F. All moths caught in traps with standard 1 mg pheromone lures will
be males. Traps with CM-DA combo lures, which
contain codlemone pheromone (the male attractant used in 1
mg lures) and a kairomone made of pear volatiles, attract only males before females emerge and both males and females thereafter.
The first sustained catch of female moths in these traps is referred to as "female
biofix", but degree-day calculations and the treatment timings are all
based on the biofix established using male trap captures, regardless of the
lure used for monitoring. To predict egg hatch, begin accumulating
degree-days from the biofix, using a lower threshold of 50°F and an upper
threshold of 88°F.
Because biofix points vary from orchard to orchard, monitor each
orchard separately to determine the biofix point for that orchard. See Table 1
for information on setting biofix points for subsequent generations.
Unless the orchard is isolated, mating disruption is most successful in large,
uniform orchards on flat ground, with a square shape (as opposed to a narrow
rectangular shape), and with relatively low to moderate codling moth
populations. It is less effective in orchards with susceptible varieties (e.g.,
Ashley, Payne, Serr, Vina) or in orchards that have a large codling moth
population history or a previous history of economically significant codling
moth damage. In these situations, make the transition to a mating disruption program
using both mating disruption and chemical control the first year or two to
reduce population levels.
Hand-applied and sprayable pheromones have been shown to work
best in orchards of moderate canopy height (25 feet or less). Aerosol pheromone
puffers are effective in orchards with both tall and short canopies.
Air
currents entering the windward sides of orchards adjacent to open areas may
break down mating disruption along orchard edges. In addition, the edges of
orchards adjacent to other walnuts not under mating disruption may have immigration
of mated female from those blocks. Monitor these situations closely, especially
in puffer-treated orchards where the distance between dispensers is large. An
insecticide spray applied 4 to 5 trees deep along the affected edge of the orchard
may help reduce the risk of damage in these areas.
Setting Out Traps
In mating disruption orchards, use codling moth
traps with CM-DA combo lures to monitor codling development and populations.
Traps baited with standard 1 mgpheromone lures catch few or no moths
when mating disruption is present.
Place
CM-DA combo traps in the mid-canopy of
trees at a rate of 1 trap per 25 acres. High counts of codling moths in
these traps will help determine the need for supplementing mating disruption
with insecticides.
Hang a smaller number of standard 1 mg traps (1 trap
per 50 acres or per block) traps to assess the effectiveness and longevity of
the mating disruptant. Hang these traps at 6 to 8 feet in the trees, If moths
are caught in these traps consistently for 2 consecutive weeks, the mating
disruptant may have broken down or expired, and chemical treatments may be
necessary.
Change
trap lures and bottoms at the frequency recommended by the manufacturer.
Setting Out Mating Disruptants
Hang aerosol pheromone puffers or hand-applied dispensers in the upper
third of the tree canopy before the historic date of first flight codling moth
biofix: in mid-March in the central and southern San Joaquin Valley to early
April further north. Re-apply hand-applied dispensers if standard 1 mg trap
catches indicate that mating disruption has broken down before the end of the
season. Aerosol puffers contain enough pheromone to last 200 days and will last
the entire season.
Sprayable pheromone should be applied at or after biofix when
leaves have started growing and are partially expanded. Sprayable formulations
have short residual activity and must be applied at 3- to 4-week intervals for
sustained mating disruption. Research to date has not shown a benefit from
applications applied at longer intervals. Make additional applications shortly
after the biofix of the second and third flights. When large populations exist
in an orchard, sprayable pheromones have been shown to reduce codling moth
damage when added to a conventional spray program. As with hand-applied
dispensers, standard 1 mg trap catches are helpful for deciding when sprayable
pheromones need to be re-applied.
Nut Sampling
Check nuts for damage during each generation, particularly near
the end of the generation when it is easier to see the frass (excrement).
Examine 1,000 mid-canopy nuts in each block (20 nuts per tree on 50 trees per
block) for signs of codling moth larval entry. Damaged nuts exceeding 1% after
the first generation or 2% after the second indicate an infestation that may
exceed 5% at harvest. In these cases supplement the mating disruption treatment
with insecticide spray during the following egg hatch of the next flight, which
is 300 degree-days after the biofix.
At harvest, collect and crack out 1,000 nuts to assess damage and to
plan for next year.
Supplemental Treatments
When making the transition from managing codling moth with
insecticides to mating disruption in orchards with high codling moth
populations (i.e., where damage in the previous season's harvest sample was
over 4%), supplement mating disruption with insecticide applications to reduce
the population. In the second year or in orchards with moderate populations
(i.e., where the previous season's damage was 2 to 4% at harvest), supplement
mating disruption with sprays of insecticides that will not disrupt populations
of natural enemies. In orchards with low populations (where the harvest damage
was less than 1% the previous season), mating disruption alone can be used.
Where insecticide sprays are needed, use degree-day calculations (see below) to
time applications for maximum effectiveness, which is when the larvae are
emerging from the eggs.
MONITORING
AND TREATMENT DECISIONS IN A CONVENTIONAL ORCHARD
In orchards treated with contact or ingested
insecticides (e.g., spinosad and oil, organophosphates pyrethroids, and
carbamates), time all treatments to kill larvae as they emerge from eggs. If
insect growth regulators are used, apply treatments before egg laying (Dimilin)
or egg hatch (Confirm, Intrepid), depending on label instructions. Use pheromone
or CM-DA combo traps, degree-days (DD), and sunset
temperatures to monitor codling moth activity and
determine when egg hatch occurs. (If nearby orchards are using mating
disruptants, use the CM-DA combo lure traps for monitoring.) The degree-day
model used in this guideline for codling moth
reflects the concept that each subsequent codling moth generation time is longer
than the preceding one.
Treatment Decisions
The need for treatment and the timing of sprays is different for
the different generations of codling moth.
First generation. The
first flight of codling moth can last a long time and have two peaks (1A and
1B). To minimize interference with the walnut aphid parasite and, in most
cases, avoid the necessity for aphid treatments, it is best to delay treatment
until the second generation or the end of the first generation (1B), especially
in later-season varieties:
- Low
populations: If damage did not exceed 3% the previous season and less than
an average of 2 moths per trap per night are being caught with 1 mg traps,
delay treatment until the second flight peak (1B). If you see an increase in
trap catches, treat when 600 to 700 DD have accumulated from biofix.
- Moderate
to high populations: If damage exceeded 3% the previous season or more than
an average of 2 moths per trap per night are being caught with 1 mg traps, plan
to treat both the 1A and 1B larvae:
- Treating
1A larvae: Apply a treatment when 300 DD accumulate after biofix, using a
short-residual material to minimize disruption of the aphid parasite, Trioxys pallidus.
- Treating
1B larvae: When you see an increase in moths caught in traps around 600 to
700 DD from the first biofix, apply a second spray when the residual period
(i.e., the length of time the insecticide controls the pest) of the first
pesticide ends. Residual periods for many of the treatment materials are listed
in the Treatment Table. In most cases a range of days is given. The actual
length of a residual period is influenced by several factors, including the pH
of the solution and the susceptibility of the population to that material. If
the population has developed any resistance to the material, then the residual
period will be shorter than it would be for a highly susceptible population.
Second and later
generations. Codling moth has two to four generations a year. Continue monitoring
with traps and accumulating degree-days (as outlined in TABLE 1) until the crop
is harvested or populations decline to below damaging numbers in September. At
the beginning of each generation, determine the biofix point for that
generation in order to predict the best treatment timing during egg hatch for
that generation.
To
time a treatment for second-generation larvae, determine the biofix for the
second generation. This generally occurs around 1060 DD from the first biofix
point. However, any increase in trap
catches after 800 DD can be considered the biofix. To better determine this
biofix, clean and service the traps around 700 DD and start checking traps more
frequently.
If
there was no second peak in the first flight of codling moth, the number of
dropped nuts can be used to determine if the second generation requires
treatment. All codling moth damaged nuts drop except when there is a second
peak of the first flight or if the weather is not hot enough. (Look for frass
at the blossom end of nuts to confirm that codling moth caused the drop.)
Examine all the nuts under the same 10 trees in an orchard block each week
during the nut drop period (4 to 6 weeks from the end of bloom). Record the
total number damaged nuts per tree (not the percent damaged). If an average of
4 or less infested nuts are found per tree, you can expect less than 5% codling
moth damage by harvest without a spray. If there are between 4 and 24 infested
nuts per tree, spray at 250 DD from the second biofix and use a short residual
pesticide. If you collect more than 24 codling moth-damaged nuts per tree,
apply a treatment as soon as eggs of the second generation start hatching (250
DD from the second biofix), and use a long residual pesticide to cover the
entire hatch period (about 1 month).
Third generation egg
hatch. A third (or fourth) generation
of codling moth eggs does not occur every year in every location. Codling moth
larvae normally go into diapause (winter dormant state) around August 22, but
in warm years and warm locations they will have already started pupation before
August 22, and these pupae will soon emerge as adults to produce a third
generation. If 650 degree-days have accumulated between the peak of the second-generation
flight and August 22, most of the codling moth will not go into diapause but
will pupate and emerge in August to early September, depending on climate.
If degree-day
accumulation data indicates a third generation will occur, use pheromone traps
to establish a third biofix point around 1100 to 1200 degree-days from the
second biofix. Apply a spray when 200 to 250 degree-days have accumulated from
the third biofix unless trap catches are high, in which case treat at 160
degree-days. If needed, apply the second spray when the residual of the
previous spray ends.
Table
1. Codling Moth Management in Walnuts.
| EVENT |
ACTION |
| FLIGHT OF OVERWINTERED GENERATION
|
Hang traps out at bud break (first week in March) and determine first flight biofix
If damage did not exceed 3% the previous season and less than an average of 2 moths/trap/night are being caught with 1 mg traps, delay treatment until the second flight peak (1B); When you see an increase in trap catches, treat when 600 to 700 DD have accumulated from biofix. |
| Low populations |
If damage
did not exceed 3% the previous season and less than an average of 2
moths/trap/night are being caught with 1 mg traps, delay treatment until the
second flight peak (1B); When you see an increase in trap catches, treat when 600 to 700 DD have accumulated from biofix. |
| Moderate to high populations |
If damage
exceeded 3% the previous season or more than an average of 2 moths/trap/night are being caught with 1 mg traps, treat both the 1A and 1B larvae. |
| First treatment (1A)1 |
Spray at 300
DD2 from first flight biofix or when small nutlets first appear, whichever is later. |
| Second treatment (1B)1 |
Look for 2nd
peak about 600–700 DD from 1st biofix by checking traps
frequently.
-
If a second peak occurs, spray when residual effectiveness of 1st treatment ends.
|
| SECOND FLIGHT
|
Determine
2nd biofix to time sprays for second-generation egg hatch.
-
Use trap
catch data to detect resumption of moth flight activity and
establish
biofix. The 2nd biofix will be when an increase occurs in trap
catches between 800–1300 DD from 1st biofix (average is 1060 DD).
-
Begin
accumulating degree-days from 2nd biofix
(Check traps frequently; trap maintenance important.) |
| Visual monitoring |
If there is
a second peak in the first flight, use visual inspection. Look at a minimum
of 10 nuts/10 trees at least 10 ft up in the canopy.
-
If less than
2% infestation in visual inspection, don't treat.
-
If more than
3% infestation in visual inspection, spray at 250 DD2 from 2nd biofix and use
short residual insecticide.
-
If there is
more than 5% infestation in visual inspection, spray at 250 DD2 from 2nd biofix and use long residual pesticide to cover entire hatch period (about 1 month).
|
| EVENT |
ACTION |
| Monitoring nut drop |
If there is
no 2nd peak in the first flight (overwintered generation), monitor
nut drop to determine the need to spray.
-
If there are
4 or less infested nuts that have dropped from the tree, don't treat.
-
If there are
4–24 infested nuts/tree, spray at 250 DD from 2nd biofix and
use short residual insecticide.
-
If there are
more than 24 infested nuts/tree, spray at 250 DD from 2nd biofix and use long residual pesticide to cover entire hatch period (about 1 month).
|
| THIRD FLIGHT
|
Time sprays
for third generation egg hatch. Use trap catch data to detect resumption of
moth flight activity. Third biofix is when trap increase occurs between
800–1300 DD from 2nd biofix (average is 1100 DD).
(Check traps frequently; trap maintenance important.) |
| Low populations |
Do not treat if there is no or little (less than 2%) evidence of canopy infestation. |
| Moderate to high populations |
Spray at 300
DD2 from 3rd biofix when there is obvious canopy infestation (more than 2%). |
| FOURTH FLIGHT
|
Time sprays
for fourth generation egg hatch. Use trap catch data to detect resumption of
moth flight activity. Fourth biofix is when trap increase occurs between
800–1300 DD from 3rd biofix (average
is 1200 DD).
(Check traps frequently, trap maintenance important.) |
| Low populations |
Do not treat if there is no or little (less than 2%) evidence of canopy infestation. |
| Moderate to high populations |
Spray at 300
DD2 from 4th biofix when there is obvious canopy infestation (more than 2%). |
| HARVEST SAMPLE
|
Collect and crack out 1,000 nuts to assess damage and to plan for next year. |
If
there was a second peak in the first flight, not all of the infested nuts will
have dropped, so visually inspect the tree canopy for infested nuts. Look at a
minimum of 10 nuts/10 trees at least 10 feet up in the canopy. If less than 2%
are infested, don't treat. If greater than 2% infested nuts are found, a treatment
is necessary. Apply an insecticide as soon as eggs of the second generation
start hatching (250 DD from the second biofix). Use a short residual material
if the percent infestation is between 3 and 5, or a long residual material to
cover the entire hatch period (about 1 month) if greater than 5% infestation is
found.
For
the third and fourth generation, the decision to treat must be based on a
combination of factors including previous treatments, number of nuts infested
in the previous generation, trap catches, and the ability to harvest early. To
determine the number of nuts infested in the previous generation, visually
inspect 20 nuts at least 10 feet up in the canopy on 50 trees. If less than 2%
are infested, don't treat. If greater than 2% are infested, treat.
If
you spray, it is important to determine a biofix for third and fourth
generations. The generation times get longer with each generation. Look for the
third biofix around 1100 DD from the second biofix and for the fourth biofix
around 1200 DD from the third biofix (the range for both biofix points is 800
to 1300 DD). Treatments are often not needed at this time; but if stings are
found on nuts, apply sprays 300 DD after the biofix.
| Common name
|
Amount to Use** |
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. |
| |
| NOTE: Residual periods mentioned in the
COMMENT sections will be influenced by many variables, including spray
coverage, weather, resistance, population pressure, etc. and may vary from
the actual effective control period, depending upon these variables.
|
| |
| MATING DISRUPTION |
| A. |
MATING DISRUPTANTS |
| |
COMMENTS: Most effective on isolated blocks or
larger blocks (more than 10 acres for hand-applied or sprayable formulations,
more than 40 acres for aerosol puffers) that have a squarish shape and low to
moderate codling moth populations, with trees of uniform size and moderate
height. Apply at first flight biofix in mid-March to mid-April. Reapply if
needed at the interval recommended on the label. Hang 1 mg pheromone traps at
6 to 8 feet high in the canopy and assess them weekly to ensure mating
disruption product has not expired. Use traps baited with CM-DA combo lures
high in the canopy to monitor population development. Check nuts for damage
after each generation and treat with insecticides if needed to ensure a low
level of damage at harvest. Be sure to monitor for other pests such as walnut
husk fly, aphids and redhumped caterpillar normally controlled by codling moth sprays. |
| |
| Aerosol puffers# |
|
|
Period of Effectiveness
(days) |
| |
Puffer CM-O |
1 puffer/2 acres |
0 |
200 |
| |
COMMENTS: The use of puffers at the lower-than-label rate of
one per 2 acres has been successfully demonstrated in orchards where a
substantial monitoring program (as described above) is carried out and supplemental
sprays are applied in the first few years, if needed, to lower codling moth
populations. Hang puffers in
the upper third of tree canopies. Hang puffers at a spacing of one per 180 to
200 linear feet in trees around the perimeter; within the orchard's interior,
place puffers in a roughly square grid pattern to achieve an interior density
of one per 2 acres. In some situations, this may result in an overall density
slightly greater than one per 2 acres. The pheromone plume released by
puffers is large and has been shown to reduce 1 mg trap catches up to 2000
feet downwind. Use CM-DA combo traps (as well as standard 1 mg traps) to
monitor conventionally managed orchards near orchards with puffers to provide an accurate assessment of codling moth population and activity. |
| |
| Hand-applied dispensers# |
|
Period of Effectiveness
(days) |
| |
Isomate C Plus |
400 dispensers/acre |
0 |
120 |
| |
Isomate CTT |
200 dispensers/acre |
0 |
120–140 |
| |
CheckMate CM-XL1000 |
200 dispensers/acre |
0 |
150 |
| |
COMMENTS: Attach dispensers to branches in
the upper third of tree canopies. Apply dispensers individually in trees at a
rate sufficient to give the recommended number of dispensers per acre. Make
application shortly before first biofix. Re-apply
hand-applied dispensers if standard 1mg trap catches indicate that mating
disruption has broken down before the end of the season.
|
| |
| Sprayable formulations |
| |
CheckMate CM-F |
2.4–4.8 oz |
4 |
NA |
| |
COMMENTS: Sprayable formulations have
short residual activity and should be applied at 3- to 4-week intervals for
continuous suppression. Delay the first application until leaves have emerged
and are partially expanded. Do not apply more than 36.2 fl oz CheckMate CM-F/acre/year. |
| |
| INSECTICIDE CONTROLS |
| High Populations Only |
| |
| A. |
METHYL PARATHION* |
| |
(Penncap-M) |
6–8 pt |
1.5–2 pt |
25 days |
14 |
| |
MODE OF ACTION GROUP NUMBER1: 1B |
| |
| |
COMMENTS: This material has a residual
activity of about 20 days and is very effective against organophosphate
(Guthion)- and pyrethroid-resistant codling moths. Repeated applications of
this material will reduce resistance levels. However, this material is
extremely toxic to honey bees. Do not apply when weeds or cover crops in
orchard are in bloom or have flower buds and bees are actively foraging in
areas to be treated. Nor should it be applied during nonforaging hours
(including nighttime) if bees have been foraging during the day. Minimum
spray interval is 21 days. Available for use under a special local needs
registration. Do not apply more than 32 pt/season or allow livestock to graze treated areas. |
| |
| Moderate to High Populations |
| A. |
SPINETORAM |
| |
(Delegate) |
4.5–7 oz |
— |
4 |
14 |
| |
MODE OF ACTION GROUP NUMBER1: 5 |
| |
COMMENTS: Larvicide. The best time to apply is at egg
hatch. Do not apply more than
0.438 lb a.i. (28 oz)/acre/year.
Do not make more than four applications per year. To reduce the development of
resistance, do not make more than three consecutive applications of any Group
5 insecticides (spinosad or spinetoram) per season and do not apply to more than one generation per season. |
| |
| B. |
CHLORANTRANILIPROLE |
| |
(Altacor) |
3–4.5 oz |
— |
4 |
10 |
| |
MODE OF ACTION GROUP NUMBER1: 28 |
| |
COMMENTS: Larvicide. The best timing is to
apply before egg hatch. Do not
apply more than 0.2 lb a.i. (9 oz)/acre/year. Do not make more than four
applications per year. To reduce
the development of resistance do not make more than three consecutive
applications of any Group 28 insecticides (anthranilic diamide) per generation per season. |
| |
| C. |
LAMBDA-CYHALOTHRIN* |
| |
(Warrior with Zeon) |
2.56–5.12 fl oz |
— |
24 |
14 |
| |
MODE OF ACTION GROUP NUMBER1: 3 |
| |
COMMENTS: Larvicide. Residual at the 5
oz/acre rate is about 21 days. Do not apply more than 0.16 lb a.i. (1.28
pt)/acre per year. Do not apply more than 0.12 lb a.i. (0.96 pt)/acre/year
post bloom. Addition of oil improves coverage and aids in suppressing mites.
During the first codling moth generation, add oil at 1% if the 1A eggs are
being treated and at 0.5% for the 1B eggs. During the second generation add oil at 0.25%. |
| |
| D. |
CYFLUTHRIN* |
| |
(Baythroid) |
2–2.4 fl oz |
0.5–0.6 fl oz |
12 |
14 |
| |
MODE OF ACTION GROUP NUMBER1: 3 |
| |
| E. |
BIFENTHRIN* |
| |
(Brigade WSB) |
8–32 oz |
2–8 oz |
12 |
7 |
| |
MODE OF ACTION GROUP NUMBER1: 3 |
| |
COMMENTS: Provides about a 21- to 28-day residual at the high label rate. |
| |
| Moderate Populations |
| A. |
FLUBENDIAMIDE |
| |
(Belt SC) |
3–4 oz |
0.75–1 oz |
12 |
14 |
| |
MODE OF ACTION GROUP NUMBER1: 28 |
| |
COMMENTS: Do not apply more than 12 fl oz/acre/crop season. |
| |
| B. |
EMAMECTIN BENZOATE* |
| |
(Proclaim 5SG) |
3.2–4.8 oz |
0.8–1.2 oz |
see comments |
14 |
| |
MODE OF ACTION GROUP NUMBER1: 6 |
| |
COMMENTS: REI is 48 hours for poling,
pruning, and thinning; 12 hours for all other activities. Do not apply more than 14.4 oz/acre/season. |
| |
| C. |
PHOSMET |
| |
(Imidan 70WP) |
5 lb |
1–2 lb |
7 days |
28 |
| |
MODE OF ACTION GROUP NUMBER1: 1B |
| |
COMMENTS: Do not apply after husk split. Provides
a residual of about 21 days. Do not apply more than 8.5 lb/acre/application or more than 5 times/season. Buffer to a pH of 5.5–6.0. |
| |
| D. |
CHLORPYRIFOS* |
| |
(Lorsban 4EC) |
4 pt |
1 pt |
24 |
14 |
| |
MODE OF ACTION GROUP NUMBER1: 1B |
| |
COMMENTS: A moderate residual insecticide
(10–14 days) best used when codling moth populations are moderate.
Effective against Guthion- and pyrethroid-resistant populations. When codling
moth trap catches are in the mid- to high range, 2 applications of this
material will be needed to cover the entire codling moth egg hatch period,
which is usually about 1 month long in later generations. Because label
restrictions allow no more than 2 applications/season, most effective control
results if both applications are directed at the same egg hatch period,
either in the 1st or 2nd generation. Provides control of the hyperparasite
that attacks the aphid parasite Trioxys
pallidus. Levels in surface waters of this material that are high enough
to be toxic to certain aquatic invertebrates have occurred following rains;
avoid runoff into surface waters. Do not make more than 2 applications/season. Do not allow livestock to graze in treated areas. |
| |
| E. |
METHOXYFENOZIDE |
| |
(Intrepid 2F) |
16–24 fl oz |
— |
4 |
14 |
| |
MODE OF ACTION GROUP NUMBER1: 18A |
| |
COMMENTS: An insect growth regulator that
provides 10 to 18 days of residual protection depending on the rate of
application and nut expansion. Kills young larvae but does not kill adult
moths. It is a reduced risk insecticide that has little or no effect on
beneficial insects and mites. Only use in orchards with low to moderate codling
moth populations. Spray coverage is extremely important. Do not apply to
large trees unless adequate spray coverage can be verified. Use no less than
100 gal water/acre for ground applications. Sprayer speed should not exceed
1.5 mph. The use of Latron B-1956, CS-7, or similar sticker/spreader is
highly recommended. Apply at the beginning of egg hatch, which is earlier
than organophosphorous or carbamate insecticide timings. It is recommended
that methoxyfenozide be applied at 200 DD after the first biofix. Do not apply more than 24 fl oz/acre/application or more than 64 fl oz/acre/season. |
| |
| F. |
ESFENVALERATE* |
| |
(Asana XL) |
9.6–19.2 fl oz |
4 fl oz |
12 |
21 |
| |
MODE OF ACTION GROUP NUMBER1: 3 |
| |
COMMENTS: Residual of about 14–21
days (lower rates have less residual activity). This is a broad-spectrum
pesticide that is harmful to beneficials at higher rates and can cause
outbreaks of aphids and mites. Lower rates may also be harmful to beneficials
but the effects of secondary pest outbreaks are less obvious. It is best to
use broad-spectrum pesticides late in the season. Provides control of the
hyperparasite that attacks the aphid parasite Trioxys pallidus, and it does not kill Trioxys. This material is not effective on scales, so if you have
a scale problem choose another chemical. Do not apply more than 0.2 lb a.i./acre/season. |
| |
| G. |
PERMETHRIN* |
| |
(Ambush) |
0.2–0.4 lb a.i. |
0.05–0.1 lb a.i. |
12 |
1 |
| |
(Pounce) |
0.2–0.25 lb a.i. |
0.05–0.0625 lb a.i. |
12 |
1 |
| |
MODE OF ACTION GROUP NUMBER1: 3 |
| |
COMMENTS: Residual of about 14–21
days (lower rates have less residual activity). There is no university data
on the effectiveness of this material on codling moth in walnuts; follow
information for esfenvalerate. This is a broad-spectrum insecticide and the
high rate will be harmful to beneficials. This material is not effective on
scales, so if you have a scale problem choose another chemical. It also may cause mite outbreaks. Do not graze livestock in treated area. |
| |
| H. |
CARBARYL* |
| |
(Sevin) |
Label rates |
12 |
14 |
| |
MODE OF ACTION GROUP NUMBER1: 1A |
| |
COMMENTS: There has been little research
on this pesticide in walnuts, but in apples carbaryl is a good codling moth
material and has a residual period of about 28 days. Carbaryl causes mites to
reproduce more rapidly, possibly resulting in mite outbreaks, so monitor for
mites if this material is used. This material is best used later in the season. |
| |
| Low Populations |
| A. |
DIFLUBENZURON* |
| |
(Dimilin 2L) |
16 fl oz |
— |
12 |
28 |
| |
MODE OF ACTION GROUP NUMBER1: 15 |
| |
COMMENTS: An insect growth regulator that
has a residual of about 21 days. It kills eggs, does not kill adult moths and
is safer to some beneficials than organophosphates and carbamates. Only use
in orchards with low to moderate codling moth populations. Coverage is
extremely important: it is not recommended for the 1st generation because the
rapid growth of leaves in spring does not allow for leaves to remain
completely covered during the residual period (21 days.) Apply in a minimum
of 125 gal water/acre and the ideal amount is 250 gal water/acre for mature
trees. Ground speed should not exceed 1.5 mph. This material must be applied
earlier than the other materials because it needs to be on the leaf before
eggs are laid. Treatment timing is before the start of the 2nd generation
fight, which is about 800–900 DD from the 1st biofix and before the
start of the 3rd generation flight, which is 1800–1900 DD from the 1st
biofix. This material is not a "stand alone" material and should be
used in combination with another control. Do not make more than 3 applications/season or apply more than 48 fl oz/season. |
| |
| Supplemental Control in Organic Orchards |
| A. |
CYDIA POMONELLA GRANULOVIRUS# |
| |
(Cyd-X, etc.) |
1–6 fl oz |
— |
4 |
0 |
| |
COMMENTS: A larvicide; time to egg hatch
at 200 to 250 DD; larvae must ingest to become infected by this virus. Make a
second application 7 to 10 days later, a third application at 600 DD, and a fourth 7 days later for a total of 4 applications per flight. |
| |
| B. |
SPINOSAD |
| |
(Entrust 80WP)# |
1.25–3 oz |
0.3–0.75 oz |
4 |
1 |
| |
MODE OF ACTION GROUP NUMBER1: 5 |
| |
COMMENTS: A short-residual insecticide.
When combined with 1% spray oil to improve spray coverage, this material is
best used as a supplement to mating disruption. May be used without oil but
may not be as effective. Only higher rates of spinosad have been tested for
codling moth control. Spray coverage is extremely important. At best,
controls 50-60% of population. Do not use more than 9 oz. of Entrust per acre
per crop. Do not apply treatments less than 7 days apart. Limited field experience in California walnuts. |
| |
. .
. PLUS . . .
|
| |
NARROW RANGE OILS# |
see label |
see label |
4 |
0 |
| |
MODE OF ACTION: Contact including smothering and barrier effects. |
| |
COMMENTS: Do not apply if trees have
suffered from a lack of adequate soil moisture or other stressing factors
(insect, disease damage, etc.) at any time during the year or if temperatures
are expected to exceed 90°F at time of application. Do not apply after husk
split. Not all oils are organically acceptable – check label and your organic certifying agency. |
| |
IMPORTANT LINKS
![[Precautions]](/IMAGES/btn-precautions_bul.gif)
![[UC Peer Reviewed]](/IMAGES/logo-ucpeerreviewed.jpg)
UC IPM Pest Management Guidelines: Walnut
UC ANR Publication 3471
Insects and Mites
C. Pickel, UC IPM Program/UC
Cooperative Extension, Sutter/Yuba counties
J. A. Grant, UC Cooperative Extension, San Joaquin County
W. J. Bentley, UC IPM Program/Kearney Agricultural Center, Parlier
J. K. Hasey, UC Cooperative Extension, Sutter/Yuba counties
W. W. Coates, UC Cooperative Extension, San Benito County
R. A. Van Steenwyk, Insect Biology, UC Berkeley
Acknowledgment for contributions to Insects and Mites:
W. H. Olson, UC Cooperative Extension, Butte County
L. C. Hendricks, UC Cooperative Extension, Merced County
G. S. Sibbett, UC Cooperative Extension, Tulare County
Acknowledgment for contributions to Codling Moth:
D. Light, USDA, Albany, CA
Top of page
|
