Codling moth management options for Michigan apples

Control options and when to use them to control codling moth this season.

June 4, 2019 - Author: and , Michigan State University Department of Entomology

Codling moth larvae in apple
Codling moth larvae in apple. Photo by Mark Longstroth, MSU Extension.

At the MSU Trevor Nichols Research Center (Fennville, MI) we set codling moth biofix on May 27, thus we can expect continued emergence of codling moth adults and widespread oviposition (egg laying), with first egg hatch (codling moth bio + 250 DD b50) predicted for the second week of June. To get the most benefit from a codling moth control measure, growers should treat a block after moth captures have been recorded and the accumulation of growing degree days (GDD) required for a particular action, as indicated in Table 1, has taken place.

Table 1. Codling Moth GDD Model and insecticide timings for control.

DD° Base 50 (Post Biofix)

Event

Action

Pink bud

Development of overwintering larvae

Set traps

0 DD° = Biofix (~200 DD° after Jan 1)

1st sustained moth captures

Set DD° = 0

100 DD°

1st generation egg laying (oviposition)

Timing for ovicide materials

250 DD°

Start of 1st generation egg hatch

Timing for larvacide materials

350 DD°

1st generation egg laying & hatch

Delayed timing if pest pressure is low, or for 2nd treatment if an ovicide was applied at 100 DD°)

500-650 DD°

Peak of 1st generation egg hatch

Timing for additional larvacide if monitoring of codling moth activity indicates a treatment is needed

1000 DD°

Expected end of 1st generation activity

 

Egg control

Although several insecticides have limited ovicidal activity, only Rimon is considered a strong ovicide material, thus codling moth egg laying is the optimal timing for this material (Table 2).  Rimon applied at codling moth biofix plus 100 DD also provides excellent control of obliquebanded leafroller (OBLR), and suppression of plum curculio (sublethal effects on subsequent generation).

Larval control 

The vast majority of insecticides used for codling moth control are aimed at killing larvae, and thus are typically applied beginning at 250 GDD post biofix (Table 2). Pyrethroid insecticides provide moderate control of codling moth and have a broad activity spectrum, but are generally avoided because their use at this stage that can result in outbreaks of phytophagous mites. Apple growers should be aware that resistance to the organophosphate (OP) compounds has been detected in Michigan orchards throughout the state, such that reliance on OP's for codling moth control is not likely to provide sufficient control. In addition, populations resistant to OP compounds may also be resistant to pyrethroids.

Delegate (spinetoram) is in the Spinosyn class of insecticides and provides excellent control of both first and second generation codling moth. It kills larvae as they hatch and begin feeding, thus should be applied at the larvicidal timings indicated in Table 1. Delegate has very good activity against OBLR, suppression activity on apple maggot (AM), and limited lethal action on plum curculio (PC) when ingested (Table 3).

Exirel (cyazypyr) and Altacor (rynaxypyr) belong to the Diamide class of insecticides that work on the insect by activating ryanodine receptors, thus depleting internal calcium and preventing muscle contraction. They provide excellent control of both first and second generation codling moth, as well as OBLR.  Exirel and Altacor also provide suppression activity on apple maggot, Exirel better than Altacor (Table 3).

The neonicotinoid Assail will provide very good control of codling moth with a residual action of 10-14 days. This compound is primarily larvicidal, but also has some ovicidal activity when applied over the top of the egg. Field trials have indicated that use of Assail in combination with pyrethroids or carbaryl can result in outbreaks of phytophagous mites. Assail is a fairly broad-spectrum material. In contrast to the insect growth regulators and Diamides, the major secondary targets of neonicotinoids are the sucking insects, specifically aphids (GAA and RAA) and leafhoppers (LH) (Table 3). The initial application of Assail targeting first generation codling moth will also provide control of plum curculio (PC), Oriental fruit moth (OFM), San Jose scale crawlers and spotted tentiform leafminer (STLM), and will control apple maggot.

Belay, another neonicotinoid registered for use in pome fruits, and Beleaf are materials labeled for first generation codling moth as well as aphids, leafhoppers, and San Jose scale. Research trials have indicated that they are not as effective for second generation codling moth.

Proclaim is a codling moth control material in the Avermectin class of insecticides. It has provided good control of first generation codling moth in trials at the Trevor Nichols Research Center and in on-farm demonstration trials. Proclaim also has very good activity against OBLR.

There are several new pre-mix insecticides labeled for codling moth control, including Voliam flexi (thiamethoxam + chlorantraniliprole), Besiege (chlorantraniliprole + lambda-cyhalothrin), Gladiator (zeta-cypermethrin + abamectin) and Leverage (imidacloprid + cyfluthrin)  that combine two active ingredients as pre-mix formulated compounds. When these are used for codling moth control care must be taken NOT to used a product in the following generation that is in the same insecticide class as either of the pre-mix active ingredients.   

Table 2. Chemical class, activity and timing of insecticides used for codling moth control.

Compound Trade Name

Chemical Class

Life-stage

Activity

Optimal Spray Timing for codling moth

Mite Flaring Potential

Imidan

Organophosphates

Eggs, Larvae, Adults

Biofix + 250 DD

L - M

Asana, Warrior, Danitol,

Pyrethroids

Eggs, Larvae, Adults

Biofix + 250 DD

H

Rimon

IGR

(chitin inhibitor)

Eggs, Larvae

Biofix + 100 DD

Residue under eggs

M*

Delegate

Spinosyn

Larvae

 

Biofix + 250 DD

 

M

Altacor, Exirel

Diamide

Eggs, Larvae

 

Biofix + 200-250 DD

 

L

Assail, Belay

Neonicotinoid

Larvae, Eggs & Adults (limited)

Biofix + 200-250 DD

Residue over eggs

M*

Beleaf

Pyrmidine carboxyamide

Larvae, Eggs & Adults (limited)

Biofix + 200-250 DD

L

Proclaim

Avermectin

Larvae

Biofix + 200-250 DD

L

Granulovirus

Biopesticide

Eggs, Larvae

Biofix + 250 DD

Residue over eggs

L

Voliam flexi

Diamide + Neonic.

Eggs, Larvae

Biofix + 200-250 DD

L-M*

Besiege

Diamide + Pyrethroid

Eggs, Larvae

Biofix + 200-250 DD

H

Gladiator

Pyrethroid + Avermectin

Eggs, Larvae,

Adults

Biofix + 200-250 DD

M

Leverage

Pyrethroid + Neonic.

Eggs, Larvae, Adults

Biofix + 200-250 DD

H

* May cause mite flaring in combination with carbaryl or pythrethroids that kill predacious mites.

Codling moth granulosis virus

Growers should not overlook including granulosis virus in their codling moth management program. This is a naturally occurring virus that goes by the scientific name of Cydia pomonella granulovirus (CpGV). Both of the two commercially available products, Cyd-X and Carpovirusine, are effective. Optimal use of the virus is against young larvae before they penetrate the fruit. The best way to target young larvae is to have the virus present on the surface of the eggs when they begin to hatch. Hatching codling moth larvae will ingest the virus as they consume their eggshells.

There are many options for incorporating virus into your codling moth management program. Deciding how much, when and how often to apply product can be quite confusing. Keep in mind the following factors when trying to sort things out: 1) CpGV must be ingested by the codling moth larva and may not kill it immediately, 2) the virus breaks down in the environment, thus a spray may only be effective for a week or so, and 3) the virus is highly lethal, a few OB's are all that are required to cause death. Our overall experience is that frequent application of a low rate of product is the best approach for using this biopesticide.

Growers can opt to use the virus as part of a multi-tactic codling moth control program. Rotating it with chemical insecticides is a good means of combating resistance. We suggest the following approaches to incorporating codling moth virus into a management program. If you want to restrict your use to a single generation, target the first generation. Some virus-infected larvae will not die immediately, allowing them to cause fruit damage and even complete larval development. Fortunately, stings or deeper entries in small fruits attacked by first generation larvae often fall off the tree or are removed by thinning. Additionally, research conducted in 2003 revealed that less than 4% of the individuals that managed to complete larval development survived to pupate and emerge as summer generation adults. Thus, applications against the first generation can greatly reduce the size of the summer generation that will need to be controlled.

Regardless of the generation targeted, it is best to make at least two applications. If you want to rotate a CpGV product with other controls, try applying a chemical insecticide as the first spray at the start of egg hatch (250 GDD) and the virus as the second spray. This is because more eggs will be present and covered by the virus spray at the later timing. The insecticide and virus could then be rotated again, or the virus could be applied weekly at a low rate for the remainder of the egg hatch period.

Table 3. Relative activity spectrum of compounds against spring and early summer apple pests

 

Primary pests

Secondary pests

Insecticide

CM

OFM

OBLR

PC

AM

STLM

GAA

RAA

  LH

SJS

Delegate

***

***

***

*

**

**

 

 

 

*

Rimon

***

***

***

*

 

**

 

 

 

 

Exirel

***

***

***

*

**

**

 

 

*

 

Altacor

***

***

***

 

*

**

 

 

*

 

Proclaim

**

**

***

 

 

***

 

 

 

 

Beleaf

**

*

 

 

 

**

***

***

**

**

Actara

*

*

 

***

***

***

***

***

***

**

Assail

***

***

 

***

***

***

***

***

***

**

Belay

**

**

 

***

**

***

***

***

***

**

Imidan

***

***

 

***

***

*

 

 

 

 

Pyrethroids

**

**

**

**

**

**

*

*

*

**

CM-codling moth, OFM-oriental fruit moth, OBLR-obliquebanded leafroller, PC-Plum curculio, STLM-spotted tentiform leafminer, GAA / RAA -green / rosy apple aphid, WALH-white apple and potato leafhoppers, SJS-San Jose scale, TPB-tarnished plant bug

* some activity, ** better activity, *** best activity relative to other insecticides

Tags: agriculture, apples, integrated pest management, msu extension


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