Mating Disruption for Management
of Oriental Fruit Moth in Stone and Pome Fruit
Table of Contents
- Introduction
- Pheromones And Mating Disruption
- Mating Disruption For Oriental Fruit Moth In Peaches
- Monitoring For Ofm In Md Peach Orchards
- Mating Disruption For Oriental Fruit Moth In Apples
- Monitoring For Ofm In Md Apple Orchards
- Considerations For Managing Ofm As A Cross-Commodity
Pest
- Summary
- Related Links
Introduction
Oriental fruit moth, Grapholita molesta (Busck), is a serious
pest of stone fruit (peach, plum, apricot and occasionally cherry) and
pome fruit (apples and pears) in most areas of Ontario. The oriental fruit
moth (OFM) is a small (about 6-7 mm), greyish-brown moth with slightly
silvery scales on its wings. A wavy pattern of light and dark scales is
noticeable on newly emerged adult OFM. Moths are generally inconspicuous
when their wings are folded (at rest).
Larvae feed on shoots or fruit depending on the crop and time of year.
Newly hatched larvae are 1.5 mm long with a black head and white body;
mature larvae are 9-13 mm in length with a brown head and pink body. There
are 3 generations per year and sometimes a partial fourth generation.
Other larvae similar in appearance that can infest stone and pome fruit
are codling moth, plum curculio and European corn borer. It is therefore
important to have larvae identified by a qualified entomologist/ crop
consultant.
Management of OFM is different in stone fruit and pome fruit orchards
because of different harvest dates, variable development of the insect
between crops, crop-specific pest complexes and established monitoring
methods. However, the background information and basic procedures for
mating disruption programs are similar for stone fruit and pome fruit.
Hiring a qualified integrated pest management (IPM) consultant to help
design and monitor a mating disruption program or any IPM program tailored
to your specific situation is a wise investment.
Pheromones And Mating Disruption
Many species of insects, including OFM, communicate by using a variety
of chemicals. Chemical signals that elicit a response from other members
of the same species are called "pheromones". "Sex pheromones"
attract one sex to the other so that mating can take place and are relatively
common in the insect order Lepidoptera (moths and butterflies). Sex pheromones
are a complex mixture of chemicals and each species has its own specific
blend. In most species, it is the female moth that emits the sex pheromone
and the male that follows the pheromone trail (or plume) to find the female.
Mating disruption (MD) technology uses synthetically produced pheromones
to confuse males and limit their ability to locate "calling"
females. If female moths do not mate, they cannot lay fertile eggs, and
if their mating is delayed, they will lay fewer fertilized eggs in their
lifetime. Consequently, the subsequent population is reduced, resulting
in less crop damage.
When planning a MD program:
- Read OMAFRA Factsheet Mating Disruption for Management of Insect Pests,
Order No. 03-079 for a full overview of mating disruption. That Factsheet
is an important companion to this one and gives essential details on
the advantages and limitations of this technology.
- Review your plan with a qualified IPM consultant familiar with MD.
- Have an IPM program in place and conduct pest monitoring for the entire
season for all pests.
- Ensure that the area to be treated is at least 4 ha (10 ac) and is
reasonably square (not a long, narrow site).
- Consult with neighbouring growers and encourage them to use MD at
the same time - larger sites are always best for MD, and "area-wide"
mating disruption programs can help reduce the threat caused by migration
of mated females from adjacent farms.
Mating Disruption For Oriental Fruit Moth In Peaches
Oriental Fruit Moth - Peaches
In peaches (and nectarines), OFM larvae feed on succulent shoots in the
first generation, infest shoots and fruit during the second generation,
and mainly attack fruit during subsequent generations. Thus, OFM is both
an indirect and direct pest of peaches. Shoot damage is called "flagging"
and is characterised by a drooping or "shepherd's crook" appearance
of shoots (Figure 1). Frass (insect excrement) and entrance or exit holes
are also usually obvious on infested shoots. In peaches, this damage can
easily be seen from the ground, with no special training or equipment.
OFM larvae readily move between peach shoots and a single larva damages
2-5 shoots during its development. Only one other pest (peach twig borer,
Anarsia lineatella Zeller) causes similar damage but it is currently uncommon
in Ontario. Peach canker and brown rot may infrequently cause somewhat
similar shoot tip death, but it is easy to distinguish these problems
on close examination, as no insect frass will be present. Monitoring for
shoot damage early in the year is a good way to determine if control methods
for OFM have been effective and to estimate the severity of the pest problem
in an orchard from year to year.
Figure 1. "Flagging" or
shoot damage on peach. Note entrance hole and frass (insect excrement)
on underside of shoot.
Mating Disruption Products
Expanded acreage MD trials (18-48 ha blocks; 45-120 ac blocks) conducted
in Ontario peach orchards showed that the technology is as effective as
the use of insecticides in minimizing damage by OFM. Methods of applying
pheromones for MD of OFM fall into 2 broad categories: hand-applied pheromone
dispensers and sprayable pheromone formulations. A thorough discussion
on both types of pheromone application technologies is contained in the
OMAFRA Factsheet Mating Disruption for Management of Insect Pests, Order
No. 03-079; review before choosing a MD product. A basic premise in using
MD is that a minimum level of pheromone must be maintained in the orchard
to prevent mating. Always follow the product label and do not reduce the
recommended rate of pheromone dispensers or amount of sprayable pheromone
used.
Hand-Applied Dispensers
The 2 main forms of hand-applied dispensers are "twist-ties"
(sometimes called "tube-type") and "clips" (or "ampoules").
There may be partial season dispensers (requiring more than 1 application
per season or other strategy as outlined below) and season-long lasting
dispensers of either type.
Application
Apply twist-tie dispensers by twisting loosely around themselves
(Figure 2) or coiling around a branch (Figure 3). Either way is acceptable
as long as they stay on the tree and are not installed in such a way as
to girdle branches. Clips are installed by simply snapping them onto branches
of an appropriate size. For MD of OFM, apply dispensers at about 2 m from
the ground or slightly higher. Do not put dispensers in exposed positions
such as on dead limbs. From experience with MD products in Niagara peaches,
it is clear that it is not absolutely critical to have dispensers in the
top third of the trees for effective MD of OFM. However, some product
labels indicate that dispensers do need to be in the top third of the
trees. That recommendation should be followed for orchards or growers
using MD for the first time and along orchard edges where possible.
Figure 2. "Twist-tie" type
hand-applied pheromone dispenser twisted around itself.
Figure 3. "Twist-tie" dispenser coiled around
branch.
Application time for hand-applied dispensers varies widely depending on
the application rate of the particular dispenser (consult the product
labels for appropriate rates). However, the largest factor determining
speed of installation appears to be worker supervision. For twist-ties,
workers should be able to cover 0.4-0.8 ha/hour (1-2 ac/hour) depending
on application rate. Clip dispensers can be applied faster but do require
the same care in branch choice. Dispensers should be put on sturdy branches
(at least 1 cm in diameter) that are least likely to be pruned later.
Worker education is also important to prevent dispensers from being cut
out of peaches during normal spring pruning operations. If the same workers
do both operations, prune-out is kept to a minimum.
Timing of Application - Peaches
Mating disruption programs usually rely on the application of pheromones
before first flight of the target pest in the spring. First spring activity
of any insect is highly dependent on weather conditions. Regional crop
and pest reports are extremely helpful in determining the correct timing
for any pest management decisions including the use of MD products.
Effective strategies verified in Ontario have been to:
- apply the products prior to flight of the overwintering generation,
with the use of supplemental insecticides directed at newly emerged
larvae, or
- to apply an insecticide for the management of first generation, followed
by application of pheromone mating disruption products for subsequent
generations.
Current OMAFRA recommendations include the use of insecticides directed
at first generation larvae, whether or not MD is used, to ensure low pest
pressure within the orchard. This is a conservative approach, and in areas
where population pressure is low, where season-long area-wide mating disruption
programs are being adopted, and where few alternative hosts are present,
it may be possible to eventually discontinue insecticide applications
for first generation OFM.
For season-long dispensers, timing of application in peaches is fairly
straightforward. Season-long dispensers require only 1 application per
year and provide approximately 120 days of effective activity. These products
must be applied before OFM flight begins, ideally a few days to a week
before expected first flight in the spring. In Niagara (in an average
year), place season-long lasting dispensers in peach orchards around mid
to late April.
For hand-applied pheromone MD products that do not last all season, there
are 2 established options for a MD or partial MD program:
- Option 1: Make a first application of product with the timing as described
above. Then apply dispensers a second time after about 80 days. This
should provide sufficient MD for even late season peaches harvested
in September (but see Limitations section below for important considerations).
- Option 2: Apply an insecticide for management of the first generation
OFM with timing as directed by regional monitoring services. Then install
dispensers in the orchard 10-14 days later to ensure MD for the remainder
of the season. Timing and efficacy of the first generation insecticide
are critical in this case. OFM populations must be low for MD to work
- you cannot correct a poorly timed first generation spray with MD.
This strategy was used successfully for 3 years in approximately 14
ha (35 ac) of commercial orchards in Niagara.
Sprayable Pheromone Formulations
Sprayable pheromone products are available in Ontario for MD of several
pests including OFM. The pheromone blends are encapsulated in microscopic
polymer capsules and released slowly over time. Sprayable pheromones can
be applied to orchards with standard spray equipment. Always check product
labels for incompatibility notices. Extensive data has not been collected
on compatibility of sprayable pheromones with other spray products, however
field experience suggests that they are compatible with most commonly
applied insecticides, miticides, and fungicides. It is preferable to apply
sprayable pheromone formulations with a nozzle pressure at or below 150
psi, although higher pressures up to 250 psi have been tested and shown
to have no detrimental effect on the formulation.
Sprayable pheromone formulations can be applied for any or all adult
flights and should be applied to orchards as soon as the first moth is
caught in pheromone traps in the spring or before first flight as indicated
by regional monitoring and pest reports. Sprayable pheromone formulations
have a shorter life span than hand-applied dispensers, although the registered
sprayable OFM pheromone formulation (3M) will generally last for an entire
adult flight period (5-6 weeks). Timing for re-application of sprayable
pheromone products is important, since the product should be on the crop
before first flight in the targeted generation. Where generations have
prolonged emergence, multiple applications may be required.
Monitoring For Ofm In Md Peach Orchards
Pheromone-baited Traps
Monitoring for OFM is conducted using pheromone-baited sticky traps.
In a MD treated orchard, male moths should not be able to find pheromone-baited
traps just as they are not able to locate female moths. However, a series
of "sentinel" traps is recommended for MD treated orchards to
ensure that the MD program is effective. Follow these points for using
sentinel traps in MD orchards:
- A minimum of 1 series of 5 traps/4 ha (5 traps/10 ac).
- One trap at the edge of the orchard and the rest of the traps at 40
m intervals following a row into the orchard.
- Place traps 1.5 m high on a sturdy branch in such a way that traps
will not spin in the wind.
- Mark all trap trees with flagging tape but keep tape and leaves out
of traps.
- Replace traps if they become water-soaked, sticky surface is depleted,
or if traps are filled with dirt or other debris.
- Replace pheromone caps every 6 weeks or as directed by the manufacturer.
- Monitor traps twice per week on the same days each time (e.g. Mondays
and Thursdays). Record and remove all OFM (remove other insects as well).
Retain records.
If no OFM are found in the traps, this is an indication that the MD program
is working. A few OFM will usually be caught in border traps. This is
not cause for alarm as the concentration of pheromones at MD block borders
is sometimes lower than required for completely effective disruption.
If more than 5 moths are found in a border trap from 1 monitoring date
to the next, pay close attention to that border: look for flagging and
fruit damage, and try to determine the source of infestation.
Consider a properly timed border application of insecticide only if the
border trap catches are persistent or if monitoring indicates damage is
occurring (see Shoot Damage Monitoring below). Base timing of such a supplemental
spray, if necessary, on regional population monitoring. Discuss any border
pesticide applications with a qualified crop consultant or provincial
specialist.
In a Niagara demonstration project of MD of OFM in peaches (2000-2002,
25 orchards grouped into 5 blocks), very few orchards had border trap
catches above 5 moths/monitoring day. Repeated sentinel trap catches above
5 moths were usually, but not always, correlated with slightly increased
flagging and fruit damage in a very restricted area at the border. Since
the damage was restricted to a small area, and was minor in nature, it
was fairly clear in these cases that the cause of the problem was nearby
sources of OFM, not an overall failure of MD in the orchards.
If you have been monitoring OFM populations using pheromone-baited sticky
traps as part of your regular IPM program, you can no longer do so once
you begin to use MD. In addition, trap catches are suppressed where hand-applied
MD dispensers were used in the previous year, although the level of pheromone
in this case is insufficient to prevent mating.
Shoot Damage Monitoring - Peaches
Sentinel traps indicate that MD is working. Identification of OFM damage
to shoots is a direct measure of success. Shoot damage assessments are
also recommended for insecticide-based management programs. Follow these
steps for shoot damage assessments:
- 1st shoot assessment: 10-14 days after the first OFM spray was called
for in your area.
- Examine 100 shoots on each of 10-12 trees/ha (4-5 trees/acre) (roughly
2% of trees if your spacing is 5.5 m (18 ft.) between rows and 3.6 m
(12 ft.) between trees).
- Choose trees randomly and examine all succulent shoots on one branch
at a time until you reach 100. Avoid the temptation to look only for
damaged shoots - that will bias your results. You want to determine
the true percentage of damaged shoots.
- Assess MD orchard borders separately. For borders, examine every 5th
tree for border row ends and every 10th tree along border rows.
- Record the number of flagged shoots keeping border and interior counts
separate.
- Shoot flagging for the first assessment should be well below 1%. If
not, consult a crop consultant or provincial specialist experienced
with MD.
- 2nd shoot assessment: 10-14 days after the 2nd OFM spray was called
for in your area.
- Assess damage as above.
- Threshold for concern for the 2nd shoot assessment is 1-2%. Even if
this threshold is reached, no pesticide is necessary or useful at this
time. However, pre-pick sprays or a cover spray at the appropriate time
for the third generation may be warranted.
Peach shoot damage assessments are an important measure of MD efficacy.
Monitoring as described above should take 2-3 hours for a 4 ha (10 ac)
site assuming minimal shoot flagging. Make additional checks by walking
around and through the MD block, looking for "hot spots" of
flagging. However, do not substitute the rigorous assessments above with
casual "walk-throughs" for damage assessments until you are
very experienced with MD and monitoring, and only if the orchard has a
verified, consistent history of low OFM damage. (Note: Remember that the
damage thresholds used in MD blocks, as well as the monitoring techniques
described herein, are also valid for conventional programs.)
Fruit Damage Assessments - Peaches
Intervention with pesticides to minimize OFM damage is impossible once
fruit damage has taken place. Once in the fruit, the larvae are protected
against any sprays. However, it is helpful to record fruit damage by any
pests and to have this information retained for future reference.
Record fruit damage monitoring separately for each peach variety if possible.
Check 100-200 ripe fruit on the tree, not on the packing line. If any
fruit have insect entrance or exit holes, cut the fruit open and identify
any larvae. Alternatively, store the larvae in 70% alcohol and have a
qualified IPM consultant identify them for you or send them to the Pest
Diagnostic Clinic for identification.
Limitations of MD for OFM in Peaches
OMAFRA Factsheet Mating Disruption for Management of Insect Pests, Order
No. 03-079 contains a thorough review of the potential limitations of
MD. Note that these limitations can be minimized or eliminated when MD
is practiced over large areas; the larger the area, the more successful
the MD program. In brief, those limitations include:
- size of area treated - minimum 4 ha (10 ac)
- timing of application - generally before first flight of moths in
the spring (and subsequent generations if using sprayable pheromones)
- shape of area - as square as possible. no long narrow sites
- initial pest population - must be low for MD to be effective
- rate of MD product - always at label recommended rate and spacing
(if applicable)
- internal sources of pests - bin piles and cull piles can be problematic
in MD orchards
- nearby sources of infestation - MD products have no or little effect
on female moths. MD cannot prevent mated females from flying into orchards
from elsewhere
- secondary pests - MD affects only the target pests
- size of plants - first year plantings are not suitable for MD, nor
are orchards with large numbers of missing trees
- temperature - pheromones dissipate faster in very hot weather
- wind and slope - areas with consistent high winds or steep slopes
may not be suitable.
One additional limitation of MD, specifically for OFM in peaches, occurs
when there are late season peaches or nectarines in areas where most fruit
have been harvested. In these cases, the few late season fruit are the
only targets left on which female moths can lay eggs. Pheromone products
generally do not affect female moths and no MD product can prevent gravid
(mated) females from flying into orchards from elsewhere. With large sites
(co-operating neighbours) this is rarely a problem, but it does become
an issue where a small MD site has late season fruit and all nearby conventional
blocks have been harvested. In that situation, growers should apply a
standard pre-pick spray to later varieties.
Mating Disruption For Oriental Fruit Moth In Apples
Oriental Fruit Moth - Apples
First generation OFM larvae will attack both apple shoots and developing
fruitlets, causing both direct and indirect damage. Feeding activity of
larvae in apple shoots does not result in the obvious flagging as observed
in peach, and is easily overlooked without close examination of terminals.
Oriental fruit moth "strikes" to apple shoots cause the terminals
to appear somewhat desiccated, with limited drooping, and to eventually
turn brown as the tissues die. Examination of affected shoots will often
reveal a small entry hole, with frass (insect excrement) present (Figure
4). Larvae may enter through the side of the shoot, through the leaf petiole,
or along the leaf mid-vein. Damage to shoots is primarily limited to that
caused by first and second-generation larvae, while shoots are still relatively
succulent. Some varieties (e.g. Mutsu) appear to be preferred over others
and may be good early indicators of OFM activity in the orchard. Research
indicates that OFM larvae typically infest a single apple shoot in completing
their development.
Figure 4. Terminal shoot damage in
apple. Note frass and ooze near entrance hole.
Figure 5. Early season OFM damage. Note entry through
calyx.
Figure 6. OFM damage on apple. Note entry into fruit
near calyx.
Fruit is attacked by all generations of OFM, with larvae entering through
both the calyx and stem ends; in apple, larvae will often exit via the
same hole through which they entered. Frass produced by the developing
larvae is often evident on the fruit surface and infested fruit develop
colour prematurely. However, late season damage can be difficult to detect,
and infested apples may get through packing lines undetected.
Oriental fruit moth larvae are very similar in appearance to those of
codling moth (CM). Both insects are white or cream coloured at egg hatch,
developing a pink hue as the larvae mature. Of the two, CM is the larger
insect; however, small larvae must be distinguished by examination of
the last abdominal segment. Oriental fruit moth possess a small, dark,
comb-like structure called an "anal comb" which can be seen
using a good quality hand lens or, if the larvae are very small, using
a microscope. It is critical that the pest is identified correctly, as
the biology and management strategies of the two pests are different.
Infested fruit should be collected and stored for examination by a qualified
consultant or entomologist. Where the larva is no longer present, the
fruit may be examined for the type of internal damage. Larval OFM generally
tunnel inside the flesh of the fruit (Figure 7) avoiding the seeds, while
codling moth larvae move directly into the seed cavity where they begin
feeding on seeds (Figure 8).
Figure 7. Fruit infested with OFM.
Note tunneling in flesh of apple.
Figure 8. Fruit infested with Codling moth. Note seed
feeding.
OFM will also attack pears, usually entering fruit from mid season through
to harvest. Pear shoots are rarely attacked. Due to the relatively late
harvest dates of some pear varieties (September or early October) apply
a MD program as described in the sections for apples.
Mating Disruption Products
For information on the types of MD products available, and instructions
on how these products should be applied, see the general information,
application techniques, and timing of application listed above in the
peach sections Hand-applied Dispensers and Sprayable Pheromone Formulations.
Timing of Application - Apples
There are several effective strategies for incorporating MD into an apple
IPM program. Apples generally have a longer growing season than tender
fruit. This may affect the choice of product(s) used and the timing of
MD applications. Keep in mind that no single product provides true "season-long"
management in apples, given the activity of the pest and the length of
time the crop remains in the orchard. Take note of label recommendations
for re-application.
Growers may choose to manage first generation OFM larvae with a registered
insecticide, and apply MD for subsequent generations. Where this strategy
is used, apply an insecticide for management of the first generation OFM
with timing as directed by regional monitoring services. Alternatively,
growers may opt for season-long management of OFM using MD. Where MD is
used as part of a season-long management program, note that dispensers
or pheromone sprays must be applied before first flight of the overwintering
generation and will need re-application during the growing season.
Petal fall insecticide sprays directed at other apple pests may also
suppress first generation OFM larvae. Consult the OMAFRA Publication 360,
Fruit Production Recommendations for a listing of registered products
recommended for managing OFM. Where OFM pressure is high, and/or organophosphate
resistance to OFM is confirmed, MD programs should include the use of
a supplemental insecticide directed at emerging first generation larvae
(i.e. apply an insecticide in addition to the MD product - first generation
only). In areas where population pressure is low, where season-long area-wide
mating disruption programs are being adopted, and where few alternative
hosts are present, it may be possible to eventually discontinue insecticide
applications for first generation OFM. Effective strategies verified in
Ontario to date have included the use of insecticides, with or without
MD, to manage first generation OFM larvae.
A partial fourth generation may develop in some years, with adult activity
into October. Even if an insecticide was used to manage the first generation
larvae, followed by a longer-lived MD product for summer generations,
re-application of a MD product or supplemental insecticide near harvest
may be required to maintain protection in some years for late-season cultivars.
Monitoring For Ofm In Md Apple Orchards
Pheromone-baited Traps
The use of pheromone traps for monitoring OFM is the same in apple (or
pear) as it is in peaches. See Pheromone-baited Traps in the peach section
of this Factsheet.
Shoot Damage Monitoring - Apples
Sentinel traps (as described in Pheromone-baited traps in the peach section)
provide a good indirect indication that MD is working; however, an important
early measure of its success is the amount of terminal (shoot) damage
in the orchard. Conduct terminal assessments for the 1st and 2nd generation
OFM, approximately 2-3 weeks after peak flight. Examine a minimum of 50
terminals from 20 trees per 4 ha (10 ac) MD block, looking for signs of
damage. No economic thresholds have been developed to correlate terminal
damage in apples with fruit damage at harvest. However, if terminal damage
is higher than 1-2%, this indicates your management strategy may not be
providing adequate control of this pest. Based on the different number
of shoots infested by a single larva in peach and apple, a 1-2% level
of terminal strikes in apple represents a higher OFM population pressure
than it would in peach.
Fruit Damage Assessments - Apples
After the larvae enter the fruit, they are protected from any sprays
and intervention with insecticides is pointless. However, recording fruit
damage from OFM can help identify weak areas of the MD program. Economic
thresholds for OFM have not been developed for Ontario apple orchards;
however, zero tolerance for infested fruit exists at the packing line.
Unlike in peach orchards, OFM will attack apples early in the season,
so conduct fruit damage assessments for each generation - this will provide
an early indication of the management program's success. Conduct damage
assessments approximately 2-3 weeks after peak flight of each generation.
Examine a minimum of 50 fruit from 20 trees per 4 ha (10 ac) MD block,
scanning carefully for any damage. Examine infested fruit for the presence
of larvae; a qualified crop consultant should identify these. Levels of
fruit damage higher than 1-2% indicate that the management strategy may
not be providing adequate control of this pest, and a supplemental insecticide
may be required for managing the subsequent generation(s). Discuss any
required remedial action with a qualified consultant or provincial specialist.
Monitoring for Other Pests - Apples
Pheromones for MD are species specific and will not affect non-target
species. OFM pheromone products will not affect other pests, such as codling
moth or obliquebanded leafroller. Activity of other pests and beneficial
insects and mites present in the orchard will also not be affected. Monitoring
for other orchard pests should continue as usual.
Limitations of MD for OFM in Apples
The limitations of MD in apples are the same as those previously mentioned
for peach, with a few additional comments.
The extended growing season, particularly in the production of late
season varieties, requires that efficacy of the product be maintained
well into October. Dispensers eventually run out pheromone and the output
required to "confuse" the males is no longer maintained. If
the MD dispensers are depleted before the end of the growing season, growers
could see significant levels of late season damage.
l Late-season monitoring is critical to managing this pest in apple; it
is often a partial fourth generation of OFM from mid-September into October
that causes the most significant crop loss in apples. The damage, often
restricted to small entry holes at the calyx or stem end, is often not
detected by picking crews or on the packing line. Plan ahead for your
late season monitoring program and have personnel available to provide
coverage until harvest is complete.
Considerations For Managing
Ofm As A Cross-Commodity Pest
Oriental fruit moth is a cross-commodity pest, infesting both stone fruit
and pome fruit. Growers with apples and peaches and/or other tree fruit
may find adopting MD simplifies the management of this pest over their
entire farm. Conventional IPM programs rely on insecticide applications
timed to coincide with peak hatch of larvae, before they enter the fruit;
MD targets the adults, limiting their ability to mate. As indicated previously,
apples have a much longer growing season than peaches, with some late
varieties being harvested in October. Leaving the crop in the orchard
means that it is potentially vulnerable to attack by third and fourth
generation OFM, if left unprotected. While MD may prevent mating in treated
blocks, it does not control egg laying by immigrating mated females. Typically,
damage is associated with border areas.
Growers choosing to apply MD to their apple blocks and insecticides to
their peach blocks must consider the risk of late-season migration between
crops. Using supplemental late-season insecticide sprays in apple blocks
may provide some solutions, the timing of which would be based on trap
counts obtained in adjacent peach blocks or from any available regional
counts.
The cross-commodity nature of this pest provides a great case for co-operation
between neighbouring growers, and for the adoption of area-wide MD programs
in a given localized fruit production area.
Summary
Oriental fruit moth, an important pest of stone fruit and pome fruit
in Ontario, can be effectively managed by using synthetic pheromones in
mating disruption programs. Mating disruption (MD) programs require planning,
monitoring and an understanding of this novel approach to pest management.
Mating disruption programs require the treatment of an area, not a single
variety or a few trees. Growers interested in using MD products should
familiarize themselves with the OMAFRA Factsheets and infosheets on this
topic including information on the OMAFRA web site.
There are important differences in MD products. Some hand-applied dispensers
have season-long activity while others require more than one application
per season. Sprayable formulations require accurate timing for re-application.
In all cases, a regular monitoring program is a prerequisite for a successful
MD program.
There are limitations to MD products, as there are for all pest management
strategies. Successful demonstration projects and experimental use of
MD in Ontario peach and apple orchards have shown that MD programs can
be effective in managing OFM in commercial orchards. The adoption of community-based,
area-wide MD programs will help to eliminate problems associated with
emigration of mated females from unmanaged areas, and will address the
management of the insect as a cross-commodity pest of stone fruit and
pome fruit.
This Factsheet was reviewed by Grant Oliver, 3M Canada; Bernie Solymar,
EarthTramper Consulting, Inc.; and Greg Stamm, CBC (America) Corp.
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