Codling Moth Protection – Tips For Controlling Codling Moths


and Becca Badgett
(Co-author of How to Grow an EMERGENCY Garden)

Codling moths are common pests of apples and pears, but may also attack crabapples, walnuts, quince, and some other fruits. Actually, it is the moth’s progeny, the larva, which cause the damage while feeding.

Controlling codling moths is important to prevent the spread of the insects and widespread orchard damage. Fruit trees need to be treated according to the codling moth life cycle to be the most effective. Then you need to find out what kills codling moths and which method is best for your gardening style.

About Codling Moths

The small brown to tan moths overwinter as larva in cracks of bark or other hidden areas. They pupate in spring and emerge winged shortly after. The moths lay eggs within three days of emergence which are tiny and nearly transparent. These hatch in 8 to 14 days. The newly hatched larvae must feed to grow and begin development towards cocooning stage.

The larva enters the fruit, chewing as they proceed to the core. After digesting the fruit, it is released as frass (excrement) that spills from the entrance hole, making the fruit highly undesirable. They feed on the fruit until they reach full growth, which is ½ inch (1 cm.) long, white with a brown head, and a pink tinge at the end. The codling moth life cycle starts anew when these fat larvae attach themselves to a surface and cocoon for winter. Codling moth control is needed to eliminate this unpleasant scenario.

How to Treat Codling Moth

You need to know if you have the pests before you figure out how to treat codling moth infestations. Codling moth traps containing pheromones (sexual hormones) that attract the codling moth can be used to determine the location where codling moth control is needed. Set these out when the tree is just blooming. If you find the moths in the trap, you will need to spray the trees or use mechanical or biological controls to prevent fruit damage.

Controlling coddling moths is done through a variety of ways. One primary form of codling moth protection on fruit trees is to avoid the use of broad spectrum pesticides. These kill beneficial insects such as some wasps, which eat the larvae. Birds are important predators of this insect and an important means of codling moth control. Make your garden bird friendly and invite your feathered friends to feast on the codling moth youngsters.

What Kills Codling Moths?

Let’s start with the obvious. Mechanical removal is one of the safest and simplest methods, but it only works if your tree is easy to access. Large plants would require you to crawl over them on a ladder and that is just not practical.

Pre-season coddling moth protection can be achieved to some degree by removing and picking up old fruits from the ground. This removes some of the larvae and prevents them from reaching adulthood and starting the codling moth life cycle all over again.

Some natural things to try are spinosad, granulosis virus, and Bacillus thuringiensis. Carabyl is a very effective pesticide, but it can also affect honeybee populations.

Controlling Codling Moths on Fruit

There are topical applications that can prevent codling moth larvae from feeding on fruit. Bags, or even nylons, slipped over developing fruit can prevent larvae from accessing and eating them.

You may also put a cardboard shield around the trunk of the tree to keep larvae from climbing up to the fruit. Larvae can’t fly or swing themselves from tree to tree, so this is actually a very practical and useful method.

Whichever way you decide to control the pests, the first offense is monitoring their existence and charting their life cycle.

Note: Any recommendations pertaining to the use of chemicals are for informational purposes only. Specific brand names or commercial products or services do not imply endorsement. Chemical control should only be used as a last resort, as organic approaches are safer and more environmentally friendly.


Codling Moth: Avoiding Fruit Worms In Your Trees

Apples have become one of the most iconic fruits in our diets, but it’s come a long from the mountains of Eurasia to kitchen tables around the world. Apples are a member of the rose family (Rosaceae) which also includes pears, peaches and quinces. For over a thousand years, growers along the silk road cultivated and traded fruits. The increase in the popularity of apples also unintentionally spread a small but destructive tag-a-long: the apple codling moth (Cydia pomonella).

The codling moth begins its life as a worm and almost everyone can relate to finding a worm in their fruit. As children, we often see imagery of the friendly green worm inside a big red apple. In France, there is a common idiom, “le vers et dans le fruit” or “the worm is in the fruit” meaning that the damage is already done. Today, the codling moth is a major pest in most places where apples are grown and can cause extensive fruit damage. They are also a serious threat to walnut growers who reportedly use 10% of their farming budget on controlling this pest.

Fruit production can often be considered advanced gardening because it requires a lot of investment in time and space. Many apple and pear trees don’t start producing fruits until a few years after planting. It can be discouraging to battle pests after waiting patiently to taste the literal fruits of your labor. In this blog, we’ll go over various methods to help you control codling moths and ultimately enjoy an abundant harvest.

Good Products For Eliminating Codling Moths:


Codling Moth on Pears

The codling moth ("codling" is an old name for a tiny apple) is a key pear and apple pest. The first adults appear at the time blossom petals fall. The adult insects lay eggs on young fruit, twigs, and leaves.

Controlling Codling Moth

Trichogramma wasp parasites will attack codling moth eggs and should be released about 10 days after any spray application. As the eggs start to hatch, the young caterpillars feed on the leaves for a few days. This is a good time to spray the tree with Bacillus thuringiensis (B.t.), which kills various leaf-chewing caterpillars. The larvae don't feed heavily on the leaves so you might consider adding one or two tablespoons of skim milk powder as a feeding enhancer to your spray mixture. After feeding on the leaves briefly, the worms enter the pears and eat for about a month. Although the fruits will be ruined that year, you should try to intercept the larvae after they leave the pear and descend the trunk to reach the soil, where they will finish their life cycle. A strip of burlap about 6 inches wide and covered with Tangle Trap (a sticky, trapping substance) can be tightly wrapped around the trunk and stapled together to form a formidable and usually lethal barrier. Several turns of corrugated cardboard around the trunk will entice many of the surviving larvae to spin their cocoons in it, and after a while you can simply remove the cardboard from the tree and burn it. If there are two or more generations of codling moths in your area, use the burlap strip as a monitor of caterpillar activity and destroy the cardboard about a month after the first larvae are caught in the trap.

Don't apply Tangle Trap directly to the tree because it will injure the bark. Woodpeckers, particularly the downy and the hairy, will eat up to half of the larvae that overwinter in the orchard area. Hang a block of suet in the trees to attract woodpeckers. Scrape off old, flaky bark by using chicken wire like a bath towel to deny winter cover to the larvae and make the birds' job that much easier.


CODLING MOTH TRAPS ^

As explained above, interrupting the mating process is key to preventing the codling life cycle from getting established on your land. If you can prevent females from mating with males, you will effectively reduce the amount of egg laying which occurs on the tree.

Yes it is true that moths can come from other areas and find your tree but this is not too likely. Since most pupa hatch close to where they fed as larva they will be attracted to the same trees that have provided food for all generations before them. Furthermore, codling moths don’t fly all too well. They are not designed to travel great distances and though they can move from one tree to another in any one orchard, once they leave that common ground they are pretty much lost. For this reason, it is safe to say that any one tree or stand of trees has a certain amount of “seed” pupa which will hatch in any one spring. Clearly impacting this first hatching can have a dramatic impact on just how many or just how few codling moths are able to develop over the course of the year.

For this reason it is imperative that you get up some CODLING MOTH TRAPS before over wintering pupa hatch. Yes, it may still be cold out, but if you want to protect your crop, it’s better to be safe then sorry. Just remember the old adage about “the early bird gets the worm”. Well, your taste in worms might not be a codling moth worm but getting them before they get your apples is what any grower would prefer!

Pheromones will remain active for 30 -60 days and each tree you’d like to protect should have a trap. Keep in mind using traps is not a method of control traps are designed to keep you “updated” as to what is happening out in your orchard. So if you have 5-10 traps set up in one acre and don’t catch a moth, you’re in good shape. But if you have one tree and one trap and catch several moths, you have a problem requiring immediate attention.


Timely placement of Codling Moth traps will assuredly cut down on the amount of egg laying which can occur. However, it is not likely that traps alone will serve to collect and kill every moth around any one or group of apple trees. If you only have one tree to protect, this same program will apply.

Remember, traps can catch a lot of males which will not be able to mate allow for egg laying females. However, some will inevitably mate and eggs are sure to find their way onto a tree or two if you have activity. To deal with this, there are varying treatments listed below. Choose a method with which you feel comfortable and one that will allow you to achieve your goal. This is largely an individual choice since apples to some are the gardens finest yield and to others are nothing but deer food.


Codling Moth

by Jay Brunner, originally published 1993, revised 2018

Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae)

Codling moth belongs to the family Tortricidae. This is one of the largest families of moths, with about 950 North American species. It includes a number of important tree fruit pests, e.g., codling moth, oriental fruit moth and several species of leafrollers. These moths are small, usually gray or brown, and their wings have bands or mottled areas. The front wings are usually square tipped. While at rest, these moths hold their wings roof-like over the body.

Codling moth originated in Asia Minor but has been a principal pest of apple and pear in North America for more than 200 years. With the exception of Japan and part of mainland Asia, it is found wherever apples are grown throughout the temperate regions of the world. Codling moth larvae bore deep into the fruit, making it unmarketable. If uncontrolled, codling moth can destroy most of the crop. By the first half of the 20th century, the codling moth was a major pest in all apple growing districts of North America. It was not until synthetic organic insecticides became available in the late 1940s that the codling moth could be maintained at very low levels in commercial orchards.

Hosts

Codling moth prefers apple but also attacks pear, large-fruited hawthorn and quince. In California, races of codling moth attack prune and walnut. Pears have some natural resistance to attack by codling moth when fruit are small because of their hardness, however, pears can become heavily infested in late summer as they mature. Infestations in stone fruits such as apricot and cherry are extremely rare and usually occur only where heavy infestations of apple or pear are nearby.

Life Stages

The codling moth egg is oval, flat and, when first laid, almost transparent. It is about 1/12-inch (2 mm) long. Eggs are laid individually on leaves or fruit and are very difficult to find, especially in a commercial orchard.

Larva

The newly hatched larva is only about 1/10 inch (2 to 3 mm) long. Its head is black, and the body is creamy white. The full grown larva is 1/2 to 3/4 inch (12 to 20 mm) long, has a brown or black head capsule and thoracic shield. The body is usually creamy white but turns slightly pink when mature. Unlike other caterpillar larvae that feed on the flesh of the fruit, such as oriental fruit moth and lesser apple worm, the codling moth larva burrows through the flesh and feeds primarily on seeds. When mature the codling moth larvae exits the fruit and searches for a sheltered location on the tree or at the base of the tree and spins a cocoon.

The codling moth pupa is brown and about 1/2 inch (12 mm) long. It resides inside a cocoon spun by the mature larva on the tree beneath bark scales or in a sheltered place at the base of the tree.

Adult

The adult codling moth is about 1/2 inch (12 mm) long. At first glance, it seems a nondescript dull gray, but closer inspection shows the wings are crossed with fine alternating gray and light-colored bands. The wings are tipped by a patch of bronze-colored scales that reflect in sunlight. The moth holds its wings tent-like over its body when at rest.

Life history

The codling moth spends the winter as a mature larva in a cocoon. Larvae are found under loose bark scales on the tree, in litter at the base of the tree, in wood piles, on picking bins in the orchard or on farm buildings near packing sheds where culled apples might have been dumped. Overwintering larvae begin changing into pupae early in the spring prior to the opening of blossoms. The first adult moths begin to emerge around the time of full bloom of Red Delicious. Peak emergence is usually 17 to 21 days later, though this depends on temperature. Adults continue to emerge for 6 or 7 weeks. Moths are most active on warm evenings, but are inactive at temperatures below 60 В°F. Moths mate and begin laying eggs within a day of emerging. First generation eggs are laid primarily on leaves, although some may be found on fruit. Eggs require 8 to 14 days to incubate.

Newly hatched larvae find fruit and enter either at the calyx end or through the side. They bore through the skin and feed on the fruit flesh for a few days, then move towards the apple core where they feed on seeds and flesh surrounding the seeds. As they feed, they push excrement out of the apple through an entry hole, which is gradually enlarged and often serves as an exit hole. Larvae are fully grown in three to four weeks, at which time they leave the fruit in search of sheltered places to spin cocoons. In our region, most larvae pupate and, in two to three weeks, emerge as second-generation adults.В However, a small percentage of first generation larvae enter diapause, a state of arrested development, and do not emerge as adults until the following spring. Second generation adults usually begin emerging in early July. Adult activity peaks in mid-July to early August and continues into early September. Second generation larvae are in the fruit from mid-July until late September. Mature larvae of the second generation leave fruit as early as mid-August in search of overwintering sites.В It has become more common to have a third codling moth generation and, in exceptionally warm years, a partial fourth generation. Moths representing a third flight emerge in late August or early September and deposit eggs. While larvae of the third generation enter fruit, causing severe levels of crop loss in some instances, most do not complete development before winter conditions arrive or fruit is harvested.

Damage

Injury is caused when larvae feed on fruit. There are two types of damage: stings and deep entries. Stings are shallow entries where a larva burrows into the flesh and then dies or a larva briefly feeds at a location then abandons that site and moves to another location. On more mature fruit, apple or pear, a reddish colored ring often forms around a new entry or sting.В Deep entries occur when a larva bores through the flesh of the fruit, eventually arriving at the center of the apple or pear where it feeds primarily on seeds. Deep entries are often characterized by brown frass, or excrement, extruding from an enlarge entry hole or a new hole destined to as an exit for the mature larva. In pear, deep entries are most often noticed when frass appears at the calyx end of the fruit. Both types of damage make fruit unmarketable, but deep entries are a problem in stored fruit because bacteria and fungi associated with the entries enhances fruit rot.

Monitoring

Pheromone traps can be used to monitor adult activity. Traps should be placed in the orchard by the pink stage of apple flower-bud development. Traps should be examined frequently until first moths are captured and then weekly thereafter. Trap placement and maintenance are critical to obtaining reliable information on which to make management decisions.

Traps should be placed in the top 1/3 rd of the tree within the canopy, making sure the entrance to the trap is not blocked.В There are various types of traps but the most common one used over the past decade is the delta-type. This trap provides efficient capture of moths and is made of durable materials that maintains its shape throughout the season. In most traps an insert with a sticky surface is where moths are captured.В Some inserts are coated with a sticky adhesive that requires stirring occasionally to maintain its effectiveness in capturing moths. Other inserts have a dry adhesive that does not require stirring. Both types of inserts should be changed if they become contaminated with dust or other debris.

There are several different lures that can be used to monitor codling moth adult activity. Most apple orchards in Washington are treated with pheromone mating disruption products and in these orchards a “high-load” pheromone lure, or a lure containing pheromone plus a non-pheromone component, such as pear ester, should be used. The lure used in a trap should be changed on the interval recommended by the company providing the product.

To assess codling moth damage, examine fruit at the end of the first generation, in early July, and again before harvest. A visual inspection of fruit viewing half of 30 to 40 fruit from least 40 trees, or in high-density orchards at 40 locations, for every 10 acres. Most fruit damage typically occurs in the upper half of trees, so sampling this region is critical.

Some growers, especially organic growers, have banded trees with cardboard strips as a means of monitoring presence and density of codling moth and as part of a control program. Mature larvae migrating down the tree in search of shelters to spin cocoons enter these bands. Bands can be removed and examined after the first generation or after harvest. If the intent is to estimate the codling moth population, banding 40 trees per 10-acre block is recommended. This technique is much more efficient on young trees with smooth bark. On older trees, the bark should be scraped smooth and the bands attached at the scraped area to enhance capture of larvae.

Treatment thresholds

Estimating the population level of codling moth in commercial orchards is challenging.В Visual observation of fruit injury can provide valuable information about the level and distribution of codling moth in an orchard.В See the discussion above for information on this method.В If fruit injury monitoring reveals injury levels of 0.5% or more then increased controls should be implemented.

Capture of codling moth adults in pheromone traps can be used to estimate population levels and help make control decisions. The number of traps used, their location, trap maintenance and the quality of the pheromone trap are all critical elements to the successful use in a threshold-based decision program.

To implement a threshold-based decision program it is essential to use one monitoring trap for every 2.5 acres. Traps should be placed in the orchard before the accumulation of 175 degree-days (or at the pink stage of apple bud development). Trap placement within the orchard and tree will influence moth captures. Avoid placing traps at the very edge of a block. It is best to place a trap in the center of each 2.5 acre section to be monitored, however, traps may be placed toward an outside border that is impacted by known history of pest high pressure. See the discussion above regarding the kind of traps and lures to be used in monitoring codling moth adults.

Traps should be checked once a week after the first moths are caught. After a total of 30 moths have been captured, or if the trapping surface becomes dirty, the trap bottom or insert should be replaced. Count the number of moths in each trap and remove moths. Record the catch separately for each trap.В The idea behind using trap catch as a treatment threshold is that sprays are applied only when moth catch exceeds certain number, the capture threshold. Two threshold methods can be used with moth capture data.

With the first method, the trap catch threshold is 2 moths captured on two consecutive weeks. Thus, if a trap catches 2 moths one week and 2 or more the next, a treatment should be applied to the area associated with the trap (2.5 acres). However, if a trap catches 2 moths, then 1 moth, then 2 moths, a spray is not recommended. This method has worked well for growers in British Columbia and Washington.

With the second method, the codling moth degree-day model is incorporated with moth capture in pheromone traps. The same density of traps is used, one trap every 2.5 acres. Moth capture in a trap is accumulated between 175 to 425 degree-days. The recommended treatment threshold is a total 5 moths, so if 6 or more moths have been captured, then the area associated with the trap should be treated at the 425 degree-day timing. If a treatment is justified based on accumulated moth captures, then moth capture accumulation is started over for the next time period, based either on the expected residue of the pesticide or over the next 250 degree-days.В Where codling moth populations are low, it may be possible to delay the treatment decision until 525 degree-days. If by 525 degree-days the moth capture threshold has not been exceeded, then a control treatment should not be applied. If the threshold is exceeded, apply a control treatment as soon as possible. Then moth capture accumulation is started over for the next time period, based either on the expected residue of the pesticide or over the next 250 degree-days.

For the second generation and beyond, the moth capture treatment threshold is reduced to an accumulation of 3 moths, because capture efficiency of pheromone traps is reduced in this time period. Start accumulating moth catch at 1175 degree-days. If 4 or more moths are captured over the next 250 degree-days, a control treatment should be applied to the area associated with the trap. If moth captures do not exceed 3 moths, a control treatment should not be necessary, and the accumulation of moth catch from zero again.

Caution:В Control treatments should be applied to the part of the orchard represented by moth capture in the trap that has exceeded the treatment threshold. However, depending on how the orchard is designed, an area larger than that represented by an individual trap may need to be treated. The use of treatment thresholds based on codling moth capture in pheromone traps usually reduces use of insecticides. The treatment thresholds recommended above should only be applied to the individual trap associated with 2.5 acres and should not be used as a threshold based on an average moth capture over the entire orchard. If trap densities are less than on every 2.5 acres, for example one trap per 5 or 10 acres, then the thresholds described above are not applicable and if used could result in unacceptable crop loss.

Biological control

The codling moth has several natural enemies, however, it is impractical to rely solely upon them to suppress codling moth populations to levels that would result in acceptable crop protection. Most conventional insecticides are toxic to the natural enemies of codling moth. Where mating disruption or soft insecticides are implemented, natural enemies, especially parasites, can be an important component of the pest management program.

Trichogramma sp. are parasites that attack codling moth eggs. These small wasps can parasitize a high percentage of eggs under favorable conditions. Another parasite, Ascogaster quadridentata, was introduced to the United States from France as a biological control for codling moth. This wasp deposits an egg in the codling moth egg, but it does not kill the codling moth until the larva is nearly full grown.

Degree-day model

Insects are cold-blooded animals and thus how fast they develop from egg to adult is driven by the temperatures they are exposed to. Degree-day models, that accurately predict the development of insects, have been used for several insects, including the codling moth. Since the early 1980s the codling moth degree-day model has been used to more precisely time insecticide applications.

In the past, a biological event, the first capture of codling moth adults in a pheromone trap, has been used to initiate the accumulation of degree-days. This biological event was referred to as the “biofix,” because it represented a biological fix point to initiated the codling moth model. Establishing a biofix for codling moth was a challenge in many orchards, therefore, WSU scientists developed a no-biofix model that accurately predicts the development of codling moth by accumulating degree-days from January 1 of each year. On average, the first emergence of codling moth adults starts at 175 (°F) degree days from January 1, so there is no need to use moth capture in pheromone traps to initiate the accumulation of degree-days. In the past, the degree-day total was set to 0 when the biofix, first moth capture, was determined. However, with the no-biofix model degree-days there is no reset of degree-days to zero.

Timing of pesticide treatments depends on the life stage targeted.

225 degree timing:The first target is the codling moth eggs.В Eggs begin to be deposited between 225-275 degree-days.В It is possible to apply insecticides, referred to as residual ovicides, between the 225-275 degree-day period.В These insecticides kill codling moth eggs that were deposited on top of residues.В Some insecticides applied at this time will also kill leafroller larvae that are present in the orchard.

Delayed first cover timing: It is also possible to apply horticultural oil at 375 degree-days, a treatment that kills codling moth eggs already deposited.В Horticultural mineral oil is referred to as a topical ovicide.В If a residual ovicide or oil is applied as outlined above, then the next time to apply an insecticide would be at 525 degree-days.В This timing if often referred to as a delayed first cover spray, which targets codling moth larvae hatching from eggs.

If no residual or topical ovicides are applied in the 225-275 or 375 degree-day timings, respectively, then insecticides should be applied at 425 degree-days, which targets the beginning of codling moth egg hatch period.

Repeat applications of insecticides in the first codling moth generation should be based on the need to suppress the pest population. The interval between successive insecticide treatments should be determined by the length of the active residue of the insecticide used. Timing for the second codling moth generation should also be based on degree-day accumulations. Moths of the second generation will being emerging at 1175 degree-days and first egg hatch will begin at 1400 degree-days. Control timing strategies used in the first generation can be applied in the second generation. The best way to utilize the codling moth model is to access the WSU Decision Aid System (www.decisionaid.systems). This computer based system automatically updates the codling moth model but it also provides management guidelines and is linked to the pesticide recommendations found in the WSU Crop Protection Guide for Tree Fruit – EB0419.

Mating disruption

Mating disruption is a standard control for codling moth applied to roughly 90% of apple acres in Washington. Pheromones applied in orchards work to disrupt or delay the ability of male codling moth to locate and mate with females, resulting in a reduction of viable offspring. The term ‘mating disruption’ is often associated with this control technique. Pheromone mating disruption has been shown to significantly reduce the amount of insecticides required to control codling moth in apple orchards.

There are several different kinds of dispensers utilized to deliver codling moth pheromone in orchards.В For many years the hand-applied dispensers were the most common pheromone delivery system. However, aerosol emitter technologies has become more common as a method of delivering codling moth pheromone in orchards. Pheromone dispensers should be placed in the orchard prior to the first moth flight in spring. The number of dispensers applied per area depends on the type of product used. Placement of dispensers should be in the upper third of the tree canopy.

Organic control programs

Control of codling moth in organic orchards is impossible without the use of pheromones (mating disruption).В However, pheromones alone are often insufficient to provide adequate crop protection, thus supplemental pesticides applications are usually needed. The number and kinds of organic pesticides for codling moth control are very limited.В The codling moth virus and horticultural oil are effective organic insecticide, but they have to be applied frequently.В These two insecticides are best used together as a tank mix application.В The insecticide Entrust (spinosad) is also an effective organic insecticide, but the number of applications per season is restricted by the label. Other botanical and biological insecticides have not been effective at controlling codling moth in organic orchards.

Materials available for apple

Excerpt from the WSU Crop Protection Guide. For timings at which each pesticide can be used refer to the Crop Protection Guide.

Materials available for pear

Excerpt from the WSU Crop Protection Guide. For timings at which each pesticide can be used refer to the Crop Protection Guide.

Use pesticides with care. Apply them only to plants, animals, or sites listed on the labels. When mixing and applying pesticides, follow all label precautions to protect yourself and others around you. It is a violation of the law to disregard label directions. If pesticides are spilled on skin or clothing, remove clothing and wash skin thoroughly. Store pesticides in their original containers and keep them out of the reach of children, pets, and livestock.

YOU ARE REQUIRED BY LAW TO FOLLOW THE LABEL. It is a legal document. Always read the label before using any pesticide. You, the grower, are responsible for safe pesticide use. Trade (brand) names are provided for your reference only. No discrimination is intended, and other pesticides with the same active ingredient may be suitable. No endorsement is implied.

Contact

Tianna DuPont, WSU Tree Fruit Extension Specialist

Tree Fruit Research & Extension Center, Wenatchee, WA


Codling Moth

Cydia pomonella

Codling moths are pests that afflict apple and pear growers in North America. Populations of codling moths can get out of hand quickly as the damage they cause is not readily visible in many instances. Orchard growers may complain of "wormy" apples this is a direct result of the tunneling damage done by codling moth larvae whereby feeding galleries filled with frass are left in the fruit.

Description & Life Cycle:

Codling moth larvae overwinter within thick cocoons in areas that shield them from harsh winter weather (e.g. under loose bark, in cracks in bark, under mulch/debris, etc.). Once temperatures warm in early spring, the larvae pupate and emerge as adults ready to mate. Codling moth adults are about 1/2" in length with gray wings containing thin, white stripes distinguished by the copper-colored band at the wing tips. Mating begins once sunset temperatures exceed 62°F. Adults are active for a few hours prior to and following sunset. Each female codling moth can lay between 30 and 70 eggs on fruit, nuts, leaves, or spurs where the eggs will hatch and the pinkish larvae will begin to feed. After maturing, larvae drop from their feeding site and seek out a suitable location to pupate. The Codling moth life cycle varies in length depending on regional temperatures. Two complete life cycles per year are common however, four complete generations have been observed in certain climates.

Commercial damage is caused by the larvae tunneling into the fruiting bodies of the plant rendering the fruit unsightly and unsellable. These larvae, when left uncontrolled, can infest up to 90% of available fruit. Late-maturing varieties are most likely to incur severe damage. Adults do not damage plants, but should be controlled as a first step in breaking up the codling moth life cycle.

Controlling Codling Moths: Successful control of codling moths requires the combination of control measures targeting egg, larval and adult stages.

Eggs Control using Trichogramma Moth Egg Parasites during the growing season when conditions allow. If Biological Control is not possible for any reason, apply oil-based sprays like Horticultural and Stylet Oils to smother unhatched eggs.

Larvae Once larvae begin feeding, control is difficult to achieve. Best results occur when cultural practices are maintained through the growing season to prevent feeding from occurring.

  • Beneficial Nematode Applications:S. feltiae beneficial nematodes have shown positive results controlling overwintering codling moth larvae, particularly in orchards with smooth-barked trees.
  • Fruit Thinning/Removal: Avoid situations where two pieces of fruit are in contact. These are common points of entry for the larvae. Reducing density of fruit will also improve spray coverage of insecticide applications.
  • Trunk Banding: Wrap tree trunks with corrugated cardboard in spring giving larvae a location to spin cocoons that can be destroyed by hand later. This is not a standalone control measure and should be done in conjunction with one or more of the other methods on this page.Tree bands can also be used to trap crawling migrating pests with sticky adhesive.
  • Fruit Bagging: Wrap individual fruit with paper bags or Maggot Barriers and seal any openings as best as you can. This is proven successful in keeping larvae off of fruit, but is energy intensive on the grower.

Adults Trap beginning early in the growing season and continue to do so past the time of last fruit production in case neighboring properties still have active populations. Pheromone Lures for male Codling moth only as well as male and female moths are widely used by the orchard industry to both monitor and control codling moth populations. The following can be done in addition to trapping:

  • Surround WP (kaolin clay) applications deter and disorient adults. It should be applied throughout the fruiting season and at 6-8 week intervals beginning prior to spotting codling moths.
  • Botanical insecticides like Pyrethrins, Azadirachtin, and Neem should only be applied once most pollination has occurred. Sprays should be applied around sunset when adult moths are most active.



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