Managing Codling Moth in Commercial Orchards

For management techniques suitable for home growers, visit Managing Codling Moth in Home Orchards.

Codling moth is the primary insect pest of apple and pear trees and can destroy an entire crop if uncontrolled. Understanding the moth's life cycle is important for determining management methods and timing of controls. Depending on temperatures, there can be up to three generations of codling moths in Montana per growing season. Using a combination of managment methods can prevent fruit damage if interventions begin early in the season (spring) and if appropriate methods are chosen and implemented at the right time. Note that in Montana, there appears to be be lower rates of codling moth damage east of the Continental Divide, particularly in remote and windy areas (Leisso et al. 2020).

Larval entry/exit holes and frass (insect poop). Photo by Patrick Clement, CC BY 2.0,via Wikimedia Commons.	Larva and frass in fruit. Photo by Joachim K. Löckener, CC BY-SA 3.0, via Wikimedia Commons.

Description and life cycle

As temperatures rise above 50°F in the spring, the first generation of moths emerge, mates, and begins laying eggs on immature fruits or nearby leaves. The winged adult phase is ½-inch-long and grayish-brown with a dark copper-colored band at wing tips. Eggs hatch into larvae ¼- to ½-inch-long with cream- to pink-colored bodies and black or brown heads. Larvae feed on young shoots and leaves and later burrow into fruit to feed on the developing seeds. Mature larvae (1/2- to 3/4-inch-long) emerge from the fruit, seek a protected site to pupate (form a chrysalis-like structure), and transform into the next generation. Moths overwinter as larvae by spinning cocoons located on the trunk in cracks and under loose bark or on the ground in debris beneath the tree. In early spring, larvae become pupae for their transformation into adult moths.

Overview video

Timing of management actions

Biofix and degree-day timeline

Management of codling moth must be timed accurately to be safe and effective. Timing of mechanical controls such as trunk banding and fruit bagging as well as chemical controls are dependent on moth life stage, which is driven by temperature. Therefore, rather than applying codling moth controls on specific calendar dates each year, we recommend using a degree-day (DD) timeline. A degree-day is any day that the temperature rises one degree above the threshold temperature at which no development of that particular insect pest can occur. In the case of codling moth, that threshold temperature is 50°F/10°C degrees. Convenient online degree-day models use a more complex formula to calculate degree-days starting from either January 1 or biofix (below). You can use the degree-day models alongside Table 2 to schedule management actions.

The term "biofix" refers to a biological event, and here we use it to indicate the date of first codling moth flight in spring at a particular location. This date is used in the degree-day models and is important because egg-laying soon follows, and the management season begins. Biofix is traditionally obtained by noting the appearance of winged adults in pheromone traps (below), but the degree-day models can also estimate biofix based on temperatures. MSU-WARC also tracks biofix at several locations around Montana and will update it on the maps below as the season begins. 

Monitoring

Delta-style codling moth pheromone trap.

Codling moth is generally requires management in commercial orchards when more than 0.5% of fruit are damaged by the pest in a given season (WSU Tree Fruit). Inspect fruit regularly for larval entry/exit holes and frass as shown in the photo above and use pheromone traps to monitor winged adult populations. Codling moth pheromone traps contain a lure infused with a scent (pheromone) that attracts male moths. These traps are used for determining population thresholds for treatment and for pinpointing biofix. 

Pheromone trap sticky insert showing trapped moths and pheromone-infused lure

Different sources recommend placing as many as four traps per acre or as few as one trap for every five acres of orchard, depending on your goals. Higher trap density will provide a greater chance of pinpointing an accurate biofix (Jones 2020b, Murray and Alston 2020a). If you are monitoring to determine treatment thresholds, place one trap central to every 2.5 acre block of orchard (WSU Tree Fruit). Note that rainy, windy, and calm weather impact moth flight or the lure’s pheromone plume, thus impacting accuracy of trap-based biofix. In these conditions, estimated biofix provided by the degree-day models can be more accurate than trap biofix (Murray and Alston 2020a).

Apple blossoms at the first pink stage

We recommend using an orange delta-type (triangle-shaped) trap with pheromone lures and multiple sticky inserts (white-colored traps attract honeybees). Order trap(s) prior to the growing season and store the lure(s) in your freezer until needed. Lure longevity in the field is 30-60 days, depending on type, so freeze additional lures if you plan on monitoring throughout the season (Murray et al. 2020c). When using mating disruption products along with pheromone traps, the standard trap lure will be ineffective. Instead, use the CMDA lure which is the pheromone+DA (pear ester) or the CMDA+AA (acetic acid), which is even more potent (Jones 2020a). Place these “supercharged” traps at the same height in trees as mating disruptors and near orchard edges (about 5-6 rows in), in CM problem areas, and in high spots (UC-IPM 2021).

Codling moth on left is larger than sage moth and has copper band at wing tips. Photo by Jay Brunner, Washington State University Entomology.

When your earliest-blooming apple or pear variety is at the first pink stage, hang trap(s) 6-7’ high and towards the exterior of the canopy, parallel to prevailing wind (Jones 2020a). Keep the trap entrance clear of leaves and branches. Moths will generally begin flying in the first week of May for Zones 5 and 6 and the second week of May for Zones 4 or lower. Since traps will be checked regularly (every 1-2 days when establishing spring biofix), they should be easy to remove and inspect. Consider using a long bamboo or PVC pole with a notch for hanging and removing traps. Record codling moth counts separately for each trap. See the photo to distinguish between codling moths and sage moths. Replace inserts when they lose stickiness or have collected too many moths for easy counting. Reshape traps if they have been distorted by wind or animals.

Once you catch your first codling moth, you have determined biofix and can begin using a degree-day model with the "trap biofix" or "biofix" option instead of estimated biofix as mentioned above. If at least two moths are captured during each of two consecutive weeks, codling moth is considered a problem and should be treated. WSU Tree Fruit provides a more accurate degree-day method for determining treatment thresholds (note that WSU uses the January 1 start date for degree-days, corresponding with the "no biofix" column in Table 2).

When using traps to determine treatment thresholds, Washington State University experts recommend one of the following two methods in their Codling Moth guide:

• Not using a degree-day model: treatment threshold = at least 2 moths captured on 2 consecutive weeks: apply sprays to the area associated with the trap (2.5 acres). For example, if 2 moths are captured the first week, 1 moth the next week, and 2 moths the third week, treatment is not recommended. Alternatively, when 4 or more moths are caught using a codlemone lure or 3 or more moths caught with pear ester during first flight (biofix), treatment (at the appropriate timings) is recommended (Knight and Light 2005).
• Using a degree-day model (refer to section A): Count moth catches between 175-425DD (using USPest model “codling moth no biofix (Jones et al 2008)” or TRAPs “Codling moth - Fixed Biofix”). If 6 or more moths are caught, then the area associated with the trap should be treated at 425DD. Clean the trap and reset count to zero for the next period of 250 degree-days (675 cumulative degree-days) or based on the expected residue of the pesticide applied at 425DD. If by 525DD the moth capture threshold has or has not been exceeded, treat or withhold treatment as indicated by moth counts and then reset counts for the next 250DD or the expected residue of the pesticide. In second and third generations, the moth capture treatment threshold is reduced to 4 or more moths; begin counting at 1175DD for second generation and proceed counting and making treatment decisions as for first generation.

Biofix and spray dates

The spray dates at the locations listed below are based on degree-days from biofix and are reported only for first chemical spray targeting emergence of first generation of codling moth larvae. Subsequent sprays should be applied at intervals according to the product label. Note that suggested spray dates may vary from year to year, and this table will be updated with new information as it is available. If your location doesn't appear in Table 1, or if your orchard is more than ten miles from any location listed on the map below, we recommend either contacting your local Extension agent using this directory or calculating site-specific degree-days to determine spray dates for the current year. 

Management methods and products

Cultural controls

Orchard sanitation and fruit thinning

Keeping your orchard floor free of dropped fruit and removing codling moth damaged fruit from your trees throughout the season can reduce overall crop damage. Fruit should be inspected for holes with frass (excrement and other waste associated with insect activity) indicating the presence of larvae. Damaged fruit should be removed and destroyed. Early removal of damaged fruit will reduce future generations of codling moth and overall damage to fruit including secondary damage from wasps and birds.

Fruit thinning is a common orchard practice that produces larger, high-quality fruit and also prevents codling moth larvae from migrating between fruit. For commercial growers, fruit thinning and crop load management will depend on tree age and the cultivar of fruit being grown. Generally, fruit should be thinned to one fruit per cluster or for every six inches of branch length, leaving no fruit touching. Fruit thinning will also discourage trees from cropping heavily one year and not a all the next (biennial bearing). For more on thinning fruit visit WSU's list of resources on crop load management.

Chemical controls

Mating disruption

Codling moth mating disruption products contain synthetic pheromone which permeates the orchard and confuses male moths in their search for females. This method is desirable for its low toxicity to humans, wildlife, and the environment but generally cannot serve as a standalone control, particularly during the first few years of use (UC-IPM 2021). Twin- or spiral-tube CM mating disruptors are most effective in orchards of 10 or more contiguous acres and aerosol dispensers in orchards of 40 or more acres (UC-IPM 2021). Jones (2020a) recommends that organic orchards of five or more acres should always employ mating disruption (in combination with other control strategies) to optimize long-term control. Note that when using mating disruption along with monitoring traps, the standard trap lure will be ineffective. See above for details.

Twin tube, spiral tube, and aerosol dispenser style mating disruption productions

Biological controls (organic)

Codling moths have natural predators (biological controls) which may be encouraged by minimizing pesticide use and cultivating native floral diversity in the orchard (Phillips 2011). There are a few commercially available CM biological controls that can be applied or released on site. The ones described below might be effective when used as part of an organic CM management program; however, these organisms have not been tested in Montana orchards. See also the section on larvicides below that discusses bioinsecticides for use in organic orchards.

Entomopathogenic Nematodes

Entomopathogenic nematodes (EPN) are tiny, naturally occurring, soil-dwelling roundworms that parasitize (infest the bodies of and derive nutrients from) various insects at the larval stage. The most effective EPN species for cooler climates is Steinernema feltiae, which can be obtained from various online retailers. De Waal et al. (2011) found that cocooned, non-pupated CM larvae were most susceptible to EPNs.

Postharvest applications in the fall could be highly effective in minimizing next season’s infestations. Applications of S. feltiae in either late September or mid-October achieved 90-95% CM larval mortality in eastern Washington apple orchards (Lacey et al. 2006). Apply EPNs in the morning when daytime temperatures will be above 50°F. Ideal conditions for EPN activity are when daytime highs will range between 68°F and 77°F, humidity is above 85%, and wind is minimal (Odendaal 2016).

Mix EPN formulations with water according to product instructions and apply with an airblast sprayer, lance applicator, or watering can onto the ground near the base of each tree. If your trees are smooth-barked, larvae prefer cocooning in the duff layer of soil around the tree. If your trees have rough, loose, or cracked bark, spray trunks and lower branch junctions as well, to a height of 3 ½’ aboveground (Kaya 1984, Jumean 2009). Make a second EPN application one week after the first.

It is critical to keep EPNs from drying out, so if humidity is not high enough, spray trunks (up to 3 ½’ aboveground) and around bases of trees with water to moisten the treatment area just prior to and for at least 24 hours afterwards (De Waal et al. 2011; Lacey et al. 2006). Lacey et al. (2006)found that using a wetting agent or humectant with the EPN application improved EPN activity, especially if combined with post-application wetting (misting every 30 minutes for four hours post application).

Trichogramma Wasps

Tiny wasps in the genus Trichogramma are parasites of various insect eggs. Organic orchards may consider using these beneficial parasitoids in combination with mating disruption (Sisgaard 2017). Note that releasing Trichogramma is not effective as a stand-alone option. Trichogramma wasps available through online retailers are generally packaged on cards which tear into multiple tabs. The cards can be refrigerated for up to one month but should not be frozen. Hang one tab per tree out of direct sunlight in early morning or evening. Optimal temperatures for parasitic wasp activity range between 65°F and 85°F. Begin treatment soon after spring biofix (and 2^nd generation biofix, if necessary) and refresh tabs every 7-10 days through the end of egg hatch or until the infestation subsides. Trichogramma minutum is recommended for orchards east of the Rocky Mountains and T. platneri for those west of the Rockies (Arbico Organics 2020).

Insecticides (conventional and organic)

Pesticides and their residues can contaminate water, air, and soil and harm the short- and long-term health of wildlife and humans. Apply insecticides only after petal fall to reduce the risk of harming pollinators. Integrate cultural controls and organic products to eliminate or minimize conventional spray applications. Pests can also develop resistance to pesticides with overuse, so alternate insecticides that have a different mode-of-action Group number (IPM Institute 2021). Read the product label, safety datasheet, and application instructions carefully. See this MontGuide for information on interpreting product labels, contact the Montana State University Extension Pesticide Education Program at (406) 994-5067, or visit their website for more information on pesticide application.

According to the Crop Data Management Systems database, there are over 100 insecticides registered for backyard or commercial agricultural use for codling moth on apple crops in Montana. These insecticides target either eggs or larvae (or both). To avoid overuse and to increase effectiveness of larvicides, we recommend either the “oil only” or “delayed first cover” approaches described below. For spray timing, refer to your chosen DD model timeline and the instructions on your product labels. Adequate spray coverage is essential and spray droplet size must be very small in order to thoroughly cover all branches, leaves, and fruit.

Horticultural Oils (ovicides)

Horticultural oils that target CM eggs are either plant- or petroleum-based, and their pest control action is mechanical rather than chemical. They work by smothering—or by depriving the eggs of air—and must adequately cover the eggs to be effective. These oils are relatively safe for humans and wildlife, evaporate quickly, degrade rapidly, and leave no toxic residue. Note that plant-based oils—such as neem—can burn leaves in sunny conditions (Skelly 2013). An “oil only” spray program involves multiple applications of horticultural oil during the first generation of egg-laying followed by single applications during the egg-laying period in subsequent generations (if necessary) (Jones 2020b). Look for products that are specifically labeled as horticultural oil. Apply any oil-based products on cloudy days or towards evening to prevent leaf burn.

Larvicides

Larvicides will not impact larvae that have already penetrated the fruit, so sprays must be precisely timed (Table 3) and thorough coverage is essential.

Conventional 

To minimize conventional larvicide applications and increase effectiveness, we recommend using either the oil only program (above) or a delayed first cover (DFC) approach which uses one application of horticultural oil to reduce egg hatch and subsequent timed larvicide sprays for controlling larvae (Table 3). 

Organic 

Organic larvicides generally have a shorter period of effectiveness than conventional sprays and therefore must be applied more frequently. Some researchers recommend designating their use to second and third generations (Jones 2020a, Murray and Alston 2020a). However, special formulations of kaolin clay (Surround) may be used effectively during first generation. Kaolin works by disorienting newly hatched larvae and making fruit and leaf surfaces less appealing for egg-laying (Unruh et al. 2000). Apply kaolin multiple times over a four-week period and combine with other management methods. In second and third generations, consider using insecticides containing Spinosad (Entrust) or CpGV (Cyd-X) and using the DFC approach mentioned above as for conventional larvicides. These bioinsecticides must be eaten in substantial quantities by young CM larvae before they penetrate fruit. Apply products on cloudy days or in late afternoons during reduced sunlight to extend their period of activity. Note that pyrethrum (a botanical insecticide) and Bt have generally been found to be ineffective by commercial growers (UC-IPM 2021).

* RUP, restricted use pesticide requires an applicator’s license. Contact the Montana Department of Agriculture or Montana State University’s Pesticide Application Program for information about pesticide applicator licensing

DISCLAIMER: These product recommendations are provided only as a guide. It is always the pesticide applicator’s responsibility, by law, to read and follow all current label directions for the specific pesticide being used. Due to constantly changing labels and product registration, some of the recommendations given in this writing may no longer be legal by the time you read them. If any information in these recommendations disagrees with the label, the recommendation must be disregarded. No endorsement is intended for products mentioned. The authors and Montana State University assume no liability resulting from the use of these recommendations.

See alsoUtah State University’s guide, “Codling Moth in Utah Orchards,” which lists commonly used CM chemicals, mode of action (MOA), and active ingredients (Murray and Alston 2020a).

Product Databases

There are several online databases that list pesticides registered for commercial use on specific crops and pests in Montana. For the first two listed below, to view the full list of products, select “Montana” as the state, “insecticide” as product type, “apple” as the crop, and “codling moth” as the pest. You can also search for product brand names or active ingredients (e.g., Spinosad).

• Agrian - Lists 120 total products for use on apple and CM, 26 of which are organic. Click on the “Advanced” button on the right of the web page to get to the search form.
• Crop Data Management Systems, Inc. (CDMS) - Lists 110 total products for use on apple and CM, 31 of which are organic.
• Montana Department of Agriculture (MDA) Pesticide Brand Search - Searches are based on product brand name, company name, active ingredient, or other factors. Since names must be entered exactly as they appear in the database to produce results, try using the * (asterisk) wildcard method to do a partial name match as MDA describes on its website. This will return all products that contain the partial phrase or words. For example:
  • Company Name: searching for “safer” brand products yields zero results; however, typing “safer*” returns 40 products within two companies (“Safer Inc” and “Safer Inc.”).
  • Brand Name: searching “*cide” returns all entries ending with "cide"; “monterey*” returns all Monterey brand products.
  • Active Ingredient: this search seems to work well without using wildcards, e.g., “Spinosad” returns all 9 products containing Spinosad. If you aren’t sure how to spell the ingredient name, the wildcard could be useful, e.g., “pyrip*” returns a list of all 15 products containing pyriproxyfen, but “pyri*” returns 19 records, meaning there are 4 products in the list that contain a chemical that is not pyriproxyfen but begins with the same four letters.

Organic Materials Review Institute (OMRI) - search brands or companies to check for OMRI organic certification and any use restrictions

Management Timeline

There are several methods for determining when to implement controls:

• Calendar date timing – This method is not very accurate but may be preferable to orchardists who do not want to use the DD method. You may contact your county extension agent for approximate calendar dates for applying CM control sprays.
• Degree-day timing – If you are comfortable using the internet or mobile apps, you can use one of the handy CM DD models described below. If you do not have internet access or are more than ten miles from the nearest DD model weather station, see section on calculating site-specific CM DD.
• Observing CM and fruit tree phenology – This method can be usedin conjunction with either method above.

CM Degree-Day Models

Online CM DD models use weather station data to predict codling moth development stages. Two models are available for Montana—UTAH TRAPs (TRAPs) and USPest. Within either model, select a weather station within four miles of your orchard for greatest accuracy (Jones 2020b). Use either of the models alongside the management recommendations on this page and in Table 3. See instructions for using the models. If there are no model weather stations within ten miles of your orchard, you may wish to calculate site-specific DD for greater accuracy (see below).

TRAPs Codling Moth DD Model

If your orchard is in Bozeman, Columbus, Corvallis, Flathead Lake, Helena, Miles City, or Stevensville, we recommend using the TRAPs DD model. In addition to DD, TRAPs also provides biofix, key moth development stages, spray timings, and is available on the web and as a mobile app for Android or iOS as "Utah TRAPs: Alerts for Pests.”

USPest Codling Moth DD Model

For other locations in Montana, use the USPestmodel to select a weather station near you and select the appropriate model option based on whether you have CM trap biofix. If you have biofix, select option “codling moth (Brunner and Hoyt 1987)” and enter biofix as a starting point of DD calculations. If you do not have biofix, choose option "codling moth no biofix (Jones et al. 2008)" to use January 1 as a starting point for DD calculations. Refer to Table 3 for timing treatments.

Calculating Site-Specific CM DD

This method of DD calculation may be used if you do not have an internet connection or are located more than ten miles from a TRAPs or USPest weather station and therefore cannot accurately use either of the online DD models. You will need to hang pheromone traps to obtain biofix and record daily maximum (max) and minimum (min) temperatures at your orchard from biofix through mid-September. If you miss recording temperatures even for a day or two, your DD timeline will lose accuracy, especially as temperatures rise and the days accumulate higher numbers of DD. A digital temperature data logger (~$150) can store past temperatures and even send data wirelessly to your mobile device.

With recorded daily max/min temperatures in hand, refer to the table provided by the University of California Statewide Integrated Pest Management Program to find the number of DD accumulated for that day. Cumulative DD is the sum of all DD from biofix to present (cumulative DD is the number you’ll use to follow along in Table 3 for timing control actions). For each subsequent day, add the current day’s accumulated DD to the total DD from the previous day to get today’s total DD (yesterday’s total DD + today’s DD = today’s total DD). Then use Table 3 for suggested actions and timing.

Table 3. USPest and TRAPs models CM degree-days (DD) and suggested treatment timing.

* OO – “Oil only” method – repeated hort oil applications during 1^st gen egg-laying and one application during 2^nd and 3^rd gen
** DFC – “Delayed first cover” approach – one application of hort oil followed by timed larvicidal sprays
† If temperatures are too cool to produce a 3^rd generation, the model DD will plateau prior to the 3rd gen DD listed above. Additionally, reduced day length after mid-September halts CM infestation.

Life stages based on http://s3-us-west-2.amazonaws.com/treefruit.wsu.edu/wp-content/uploads/2018/07/opm_table6a.png
Spray timing based on http://treefruit.wsu.edu/article/how-to-effectively-manage-codling-moth/

Disclaimer: These recommendations are provided only as a guide. It is always the pesticide applicator’s responsibility, by law, to read and follow all current label directions for the specific pesticide being used. Due to constantly changing labels and product registration, some of the recommendations given in this writing may no longer be legal by the time you read them. If any information in these recommendations disagrees with the label, the recommendation must be disregarded. No endorsement is intended for products mentioned. The authors and Montana State University assume no liability resulting from the use of these recommendations.

Citations

Arbico Organics. 2020. Moth Egg Parasites. Accessed December 15, 2020. https://www.arbico-organics.com/category/moth-egg-parasites.

Brunner, J., S. Hoyt, and M. Wright. 1987. Codling moth control – A new tool for timing sprays. Extension Bulletin 1072, Washington State University.

Crop Data Management Systems. 2020. Accessed December 29, 2020. http://www.cdms.net/

De Waal, J., A. Malan, and M. Addison. 2011. Evaluating mulches together with Heterorhabditis zealandica (Rhabditida: Heterorhabditidae) for the control of diapausing codling moth larvae, Cydia pomonella (L.) (Lepidoptera: Tortricidae). Biocontrol Science and Technology. 21.3: 255-270. https://doi.org/10.1080/09583157.2010.540749

IPM Institute of North America. 2020. What is Integrated Pest Management? Accessed November 18, 2020. https://ipminstitute.org/what-is-integrated-pest-management/

Jones, V., M. Doerr, J. Brunner. 2008. Is Biofix Necessary for Predicting Codling Moth (Lepidoptera: Tortricidae) Emergence in Washington State Apple Orchards? Journal of Economic Entomology 101.5: 1651-1657. https://doi.org/10.1093/jee/101.5.1651

Jones, V. 2020a. How to Effectively Manage Codling Moth.  Washington State University Tree Fruit Research Center. Accessed December 24, 2020. http://treefruit.wsu.edu/article/how-to-effectively-manage-codling-moth/?print-view=true

Jones, V. 2020b. CM Information. Message to Rachel Leisso. December 2, 2020. E-mail.

Knight, A., and D. Light. 2005. Developing action thresholds for codling moth (Lepidoptera: Tortricidae) with pear ester- and codlemone-baited traps in apple orchards treated with sex pheromone mating disruption. The Canadian Entomologist, 137(6), 739-747. https://doi.org/10.4039/n05-040

Lacey, L., S. Arthursa, T. Unruha, H. Headricka, and R. Fritts Jr. 2006. Entomopathogenic nematodes for control of codling moth (Lepidoptera: Tortricidae) in apple and pear orchards: Effect of nematode species and seasonal temperatures, adjuvants, application equipment, and post-application irrigation. Biological Control 37.2: 214–223. https://doi.org/10.1016/j.biocontrol.2005.09.015

Leisso R., C. Anderson, T. Novak, K. Mendrey, O. Soller, Z. Miller. 2020. Montana surveys of codling moth damage to apple fruit 2019-2020. Dryad, Dataset, https://doi.org/10.5061/dryad.pnvx0k6k7

Leisso R., K. Mendrey, T. Novak, C. Anderson, S. Perrin, A. Kapus, A. Darling, Z. Miller. 2020b. Montana codling moth trap-based biofix compared to two fixed biofix models, 2018-2020. Dryad, Dataset, https://doi.org/10.5061/dryad.h18931zjc

Murray, M., and D. Alston. 2020a. Codling Moth in Utah Orchards. Utah State University and Utah Plant Pest Diagnostic Laboratory (ENT-13-06). Accessed November 18, 2020. https://digitalcommons.usu.edu/extension_curall/880/

Murray, M. and D. Alston. 2020b. Codling Moth Mating Disruption. Utah State University Extension. Accessed November 18, 2020. https://extension.usu.edu/pests/research/codling-moth-mating-disruption

Murray, M., et al. 2020c. Intermountain Commercial Tree Fruit Production Guide. PDF file. Accessed November 27, 2020. https://intermountainfruit.org/files/IntermountainTFG-2020.pdf.

Odendaal, D., M. Addison, and A. Malan. 2016. Evaluation of Above-Ground Application of Entomopathogenic Nematodes for the Control of Diapausing Codling Moth (Cydia Pomonella L.) Under Natural Conditions. African Entomology 24.1: 61-74. https://doi.org/10.4001/003.024.0061

Phillips, M. 2011. The Holistic Orchard: Tree Fruits and Berries the Biological Way. Chelsea Green Publishing. White River Junction, Vermont, U.S.A.

Sigsgaard, L., A. Herz, M. Korsgaard, and B. Wührer. 2017. Mass Release of Trichogramma Evanescens and T. Cacoeciae Can Reduce Damage by the Apple Codling Moth Cydia Pomonella in Organic Orchards under Pheromone Disruption. Insects (Basel, Switzerland) 8.2:41. https://doi.org/10.3390/insects8020041.

Skelly, J. 2013. Horticultural Oils – What a Gardener Needs to Know. University of Nevada, Reno, Extension FS-13-20. Accessed November 18, 2020. https://extension.unr.edu/publication.aspx?PubID=3029

UC-IPM 2021. Agriculture: Apple Pest Management Guidelines: Codling Moth (Cydia pomonella). Accessed January 15, 2021. https://www2.ipm.ucanr.edu/agriculture/apple/Codling-moth/

Unruh, T., A. Knight, J. Upton, D. Glenn, and G. Puterka. 2000. Particle Films for Suppression of the Codling Moth (Lepidoptera: Tortricidae) in Apple and Pear Orchards. Journal of Economic Entomology 93.3: 737-43. https://doi.org/10.1603/0022-0493-93.3.737