How to Control Codling Moth in the Garden

The codling moth is a serious pest for home gardeners growing apples, pears, and other fruits. Left uncontrolled, these small gray moths can ruin fruit crops by laying eggs inside developing fruit. The larvae hatch and tunnel through the flesh, ruining the fruit. Controlling codling moth organically can be challenging, but with persistence and a multi-pronged approach, you can protect fruit from damage.

Understand the Codling Moth Life Cycle

To control codling moth effectively, it helps to understand its life cycle.

Adult moths emerge from overwintering sites in spring and lay eggs on developing fruit and leaves.
The tiny larvae hatch in about a week and immediately burrow into the fruit, feeding on the flesh and seeds. The tunneling causes damage.
After 3-4 weeks, mature larvae exit the fruit to spin a cocoon, called a hibernaculum, under bark or debris.
A new generation of moths emerges after pupating for 1-2 weeks, and the cycle repeats through summer into fall.
As cold weather approaches, larvae seek protected sites to overwinter as pupae until spring.

Key steps for control target different life stages to break the reproductive cycle.

Remove Overwintering Sites

Codling moth larvae overwinter as pupae under loose bark, in debris, and in neglected fruit mummies left on trees.

In late winter, thoroughly clean up the garden:

Prune trees to remove dead wood and suckers where larvae hide.
Rake up fallen leaves, tall grass, and mulch where cocoons occur.
Dispose of plant debris by burning, solarizing under plastic, or hot composting to kill larvae.
Remove any abandoned fruit still on trees or the ground. These are prime shelters for overwintering codling moth.

Eliminating protected overwintering sites exposes larvae to predators and weather and reduces the spring population.

Install Pheromone Traps

Pheromone traps use the scent of the female moth to attract males, preventing them from breeding:

Hang traps coated with sticky glue in trees by early spring before moths are active.
For large trees, use 3-4 traps per tree. Small dwarf trees may need only 1 trap.
Position traps at eye level, shaded in foliage around the perimeter of the tree’s canopy to intercept flying moths.
Check traps weekly. Replace as they fill with moths or debris affects stickiness.
Dispose of trapped moths immersed in soapy water to prevent escapes.

Trapping males won’t eliminate codling moth but helps reduce mating success and the next generation. Use in combination with other tactics.

Apply Kaolin Clay

Kaolin clay coats fruits with a fine mineral barrier. Research shows it repels codling moth, including:

The white mineral powder deters feeding and egg laying on treated surfaces.
It disrupts moth activity through irritation and distraction.
Fruit coating may also obstruct larvae entry after hatching.
Natural kaolin clay products are approved for organic use. Brands include Surround and Harvest Guard.
Apply kaolin clay weekly starting when fruit is marble-sized through harvest. Full coverage is essential.
Reapply after rain as needed to maintain the protective coating on developing fruits.

Kaolin clay can suppress damage moderately but works best with additional measures.

Install Fruit Bags

Fine mesh fruit bags provide a physical barrier, preventing moths from accessing fruit to lay eggs.

Use knee-high bags sized for the fruit. Choose a breathable, lightweight fabric.
Bag individual fruits, cluster bag, or slip bags over entire small branches.
Install bags after petal fall when fruit is pea-sized, before moth flight begins.
Keep bags on until harvest. Check periodically for rips, holes, or openings at the ties.
Remove bags gently to avoid rubbing off protective kaolin clay coatings.

Bags combined with kaolin offer very effective codling moth protection for organic and backyard gardens.

Apply Neem, Spinosad, or Btk

Botanical insecticides derived from neem oil, spinosad, and Bt (Bacillus thuringiensis var. kurstaki) provide additional codling moth control:

Neem Oil

Neem oil disrupts the molting and maturity of moth larvae when ingested.
Multiple applications are needed, starting when moths are first active through late summer.
Neem oil also repels moths from laying eggs and feeding.
Spray neem to “runoff” for full fruit and leaf contact. Reapply after rain.
Neem oil is approved for organic gardens. Brands include Natria Neem Oil.

Spinosad

Spinosad is a biological insecticide derived from soil microbes.
It is toxic to codling moth larvae but approved for organic use at designated rates.
When larvae ingest leaves or fruit coated with spinosad, they die after a few days.
Make 1-3 applications spaced 7-14 days apart from petal fall through August.
Monitor for new damage and reapply if needed. Spinosad brands include Monterey Garden Insect Spray.

Bt (Bacillus thuringiensis var. kurstaki)

This microbial biological insecticide is effective but must be ingested to work.
It is most useful when applied during peak moth flight and egg laying to target hatching larvae.
Spray Bt thoroughly on foliage, fruits, trunks, and branches.
Multiple applications 7-10 days apart may be needed for ongoing control through the season.
BtK is approved for organic gardens. Brands include Dipel and Monterey Bt.

Using a combination of these organic insecticides with other tactics often brings the best suppression of codling moth damage.

Monitor with Pheromone Lures

In addition to trapping, specialized pheromone lures can help monitor codling moth activity:

Hang lures in trees by bloom time to detect the first flights of adult moths each season.
Choose clear delta, wing, or tube lures loaded with codling moth scent (codlemone).
Check lures twice weekly for any moths caught on the sticky surface. This signals egg laying will soon follow.
Apply Bt spray, neem, or spinosad 7-10 days after catching the first moths. Reapply every 1-2 weeks.
Monitor lures all season to time insecticide sprays precisely when needed.

Pheromone lures provide an early warning to trigger control measures before damage begins.

Use Biological Control

Beneficial predators and parasites that attack codling moth can supplement control efforts:

Trichogramma wasps parasitize codling moth eggs, killing them before they hatch. Release these tiny wasps per supplier instructions.
Green lacewings devour moth eggs and small larvae. Attract them with flowering plants. Ensure safe insecticide use if enhancing naturally occurring populations.
Birds, bats, and many common garden predators like spiders feed on codling moth larvae and adults. Avoid broad-spectrum insecticides to conserve these natural biocontrols.
Steinernema carpocapsae beneficial nematodes seek out and kill overwintering larvae in soil and debris. Apply from mid-August through fall.
Bacillus thuringiensis var. aizawai targets larvae in fruit. It is more effective inside tunnels than Bt-kurstaki.

Integrating predators, parasites, and microbial insecticides bolsters the biological control of codling moth. Monitor their impacts along with crop damage.

Remove Infested Fruits

Despite best efforts, some codling moth damage may still occur. Removing infested fruits from the garden helps minimize the spread and break the breeding cycle.

Check developing fruits frequently for entry holes with protruding “frass” (larval excrement).
Dislodge larvae by jarring limbs over a collecting frame. Mature larvae will exit and spin cocoons.
Pick off and destroy fallen fruits with signs of larvae. Cut open suspect fruits – small black larvae and brown tunnels confirm infestation.
Collect and seal infested fruits in plastic bags to solarize in hot sun, killing larvae inside.
Remove all mummified fruits remaining on trees after harvest. These shelter overwintering larvae.

While labor intensive, removing infested fruits eliminates developing larvae and limits next season’s population.

Maintain Tree Health

Vigorously growing, healthy fruit trees are less susceptible to codling moth damage:

Fertilize in spring with organic compost or fertilizers to promote lush foliage and rapid shoot growth.
Water trees regularly during dry periods for strong fruit development. Stressed trees are more vulnerable.
Prune annually during dormancy to improve air circulation and light penetration. Thin overcrowded branches.
Control other pests that stress trees, like aphids and mites, and diseases like apple scab. Reduce stress and attract beneficials.
For young or dwarf trees, provide stakes for support and minimize blowing fruit contacts that dislodge larvae.

While not a direct control tactic, optimizing tree vigor strengthens the orchard environment for resisting codling moth.

Work Cooperatively with Neighbors

Since codling moths can fly in from broader areas, it helps to organize area-wide efforts:

Talk to backyard neighbors about codling moth issues and control efforts. Coordinate timing of key organic sprays.
Trade excess fruits to minimize unmanaged trees serving as reservoirs of infestation. Share monitoring data and observations.
Advocate for community-level monitoring networks and outreach to expand adoption of control practices.
For commercial orchards, discuss organic protocols with the manager and chances to collaborate on regional pest management.

Getting surrounding growers involved helps limit reinfestation and amplifies the positive impacts of your codling moth control efforts.

Review Progress and Adjust Annually

At the end of each growing season, take time to review monitoring records and evaluate results:

Did pheromone traps catch high or low populations? More than the previous year?
How effective were kaolin clay treatments in deterring infestation? Did fruit bagging work well?
Were there certain problem areas of the orchard or times of year when control fell short?
What impact did beneficial insects appear to provide?
Does anything need adjustment for next year? Different control products, application method or timing, tree care practices?

Analyze the season’s effectiveness annually and make changes to improve the integrated organic system for your situation. With diligence, codling moth can be successfully managed.

Frequently Asked Questions About Controlling Codling Moth

Here are answers to some common questions about codling moth control:

How do I know if I have codling moths?

Look for signs of damage – holes with frass exuding from fruits. Hang pheromone traps in spring to catch adult male moths and monitor for activity.

What is the best organic spray for codling moths?

A combination of insecticides like neem oil, spinosad and Bt provides the most effective control when rotated over the season.

When should I spray for codling moth?

Target spray treatments from just before bloom through late summer when larvae are active, about every 7-14 days. Monitor pheromone lures to time applications.

Do codling moths affect other fruits besides apples and pears?

Yes, they may also infest quince, apricots, plums, peaches, and other thin-skinned orchard fruits.

How can I get rid of codling moth larvae in fruit?

Removing infested fruits quickly helps limit spread. Solarizing sealed bags of fruit helps kill larvae inside. till soil around trees in fall to destroy overwintering cocoons.

What attracts codling moths?

Virgin female moths emit a scent (codlemone) that attracts males for breeding. Pheromone traps and lures exploit this attraction response to monitor and control moths.

Do codling moths migrate in spring?

No, they overwinter as pupae in protected sites near host trees and emerge locally as temperatures warm. Cleaning gardens in winter helps reduce local populations.

How many generations of codling moth per year?

In temperate climates, codling moth normally produces 1-2 generations per season. Further south, additional partial generations are possible. Timing controls for continual moth activity is important.

Can codling moths be controlled without spraying?

Yes, combining techniques like fruit bagging, pheromone disruption, kaolin clay barriers, biological control, and sanitation can substantially limit damage without sprays in smaller plantings.

Conclusion

Controlling codling moth organically involves diligent monitoring, proper timing of treatments, and persistence in implementing multiple complementary tactics. The good news is that gardeners can succeed in protecting high value fruits from damage through an integrated pest management approach. Paying close attention to the details of codling moth seasonal biology allows you to break their breeding cycle. Combining proven physical, biological, and least-toxic spray options keeps trees and fruits healthy and productive. With observation and effort, you can manage codling moth infestations and enjoy bountiful harvests.