July 10, 2024

Based on degree-day accumulations, the codling moth  degree-day (DD) model predicts that second generation adult emergence is about 30% and 60% complete in Henderson County (1533 DD) and Cleveland County (1890 DD). Unless captures in pheromone traps consistently average more than 5 moths/week, it is unlikely that more than two insecticide applications will be necessary against the second generation. If trap captures remain consistently low, one application may suffice.

Orchards treated with mating disruption generally do not require insecticide treatments for the second generation, although pheromone trapping is recommended to account for the unexpected.

First generation brown marmorated stink bug adults are predicted to begin emerging this week in lower elevation orchards such as Cleveland County, where 750 DD is predicted to occur on Saturday. If concerned about damage from this pest, next week would be optimum timing for a pyrethroid application. Populations have generally been low thus far, but that is not always a good predictor of the intensity of first generation adult populations. In Henderson County where DD accumulations have only reached 540, it’ll be several more weeks before adult emergence begins.

Learn more about southeastern apple insect pests at the Apple Insect Management page.

2024 Average Weekly Trap Captures

*Note that these averages illustrate only the timing of insect emergence and fluctuations in populations, and are not representative of population levels in any given orchard. The only way to have an accurate assessment of an individual orchard’s populations is to set up traps in that orchard.

2024 Accumulated Degree Days

About degree-day models

June 27, 2024

It’s Time for Second Generation Codling Moth

Current Conditions: In lower elevation orchards (i.e., less than about 1400 feet, such as Cleveland County), second generation codling egg laying has started (cumulative DD are at about 1480). In higher elevation orchards such as Henderson County, where DD accumulations are at about 1180, and it will be another 7 to 10 days before egg laying is predicted to begin. Egg laying in the southeast begins between 1400-1450 DD

Determining the Need for Insecticidal Control: Remember that the codling moth degree-day model is a tool to aid in timing insecticide sprays to coincide with egg hatch of respective generations. It does not predict the need for sprays. Codling moth populations vary widely from location to location, and insecticidal control is not necessary in orchards with extremely low populations. Conditions in which populations are at extremely low density and where insecticidal control is most frequently NOT needed for the second generation include:

1) Orchards where mating disruption has been used for multiple years and there is no evidence of damage by the first generation. Regular use of mating disruption greatly suppresses populations and can lead to near local extinction.

2) Non-mating disruption orchards that also have low populations, characterized by the absence of damage from first generation larvae (i.e., infested fruit) and low pheromone trap captures.

Pheromone trapping is an essential tool to gauge population densities and the need for insecticidal sprays. If mating disruption is not used, a conservative threshold to dictate the need for sprays is 5 moths per trap per week (using a CM L2 lure). In mating disruption orchards, the capture of 3 moths per trap cumulatively over a two-week period warrants an insecticide application.

Insecticide Resistance Management: Since 2008, chemical control of codling moth has relied primarily on insecticides in two different classes: the diamides (Altacor, Exirel, and Verdepryn) and spinosyns (Delegate). Alternating the use of these two groups of insecticides against the different generations has likely contributed to the long-term effectiveness of these products. As a reminder, reserve one class of products against the first generation and the other for the second generation. For example, if Altacor (or Exirel or Verdepryn) was applied during the first generation, do not use these products during second generation flight, but instead apply Delegate. Alternatively, if Delegate was applied against the first generation then use the diamides during second generation flight. The goal is to avoid exposing the same generation to both types of products.

Learn more about southeastern apple insect pests at the Apple Insect Management page.

2024 Average Weekly Trap Captures

*Note that these averages illustrate only the timing of insect emergence and fluctuations in populations, and are not representative of population levels in any given orchard. The only way to have an accurate assessment of an individual orchard’s populations is to set up traps in that orchard.

2024 Accumulated Degree Days

About degree-day models

*Note that these averages illustrate only the timing of insect emergence and fluctuations in populations, and are not representative of population levels in any given orchard. The only way to have an accurate assessment of an individual orchard’s populations is to set up traps in that orchard.

2024 Accumulated Degree Days

About degree-day models

Based on degree-day accumulations (850 in Henderson and 1130 in Cleveland Counties), first generation codling moth egg hatch is essentially complete. However, some orchards, particularly at higher elevations, may have late-emerging or large codling moth populations that require continued insecticide treatments. Pheromone trap captures are the best method for gauging the need for additional insecticides during this period. Although many factors can affect pheromone trap captures, between 5 and 10 moths over a one week period can serve as a conservative threshold level.

As mentioned last week we have entered that period when several indirect pests are the major drivers of pest management decisions for the next few weeks. European red mite, apple aphids and potato leafhopper, all of which may or may not develop to damaging levels, should be the focus of monitoring programs at this time. To date aphids and leafhoppers have been below damaging levels in most orchards. Where present, mites populations could increase rapidly with the warm and dry conditions predicted in the near future. Applying miticides based on a threshold level of between 5 and 10 mites per leaf at this time will prevent populations from reaching damaging levels.

Learn more about southeastern apple insect pests at the Apple Insect Management page.

2024 Average Weekly Trap Captures

*Note that these averages illustrate only the timing of insect emergence and fluctuations in populations, and are not representative of population levels in any given orchard. The only way to have an accurate assessment of an individual orchard’s populations is to set up traps in that orchard.

2024 Accumulated Degree Days

About degree-day models

May 1, 2024

Codling Moth: Apples range from post petal fall to first cover throughout the region, with egg hatching beginning in lower elevations. Cumulative degree-days (DD) range from about 160 in Henderson County to 285 in Cleveland County. With egg hatch underway in lower elevations (e.g., <1500 ft), an initial insecticide targeting codling moth may be necessary if not using mating disruption or not monitoring populations with pheromone traps to obtain information on the intensity of populations. Based on the weather forecast, 250 degree days (beginning of egg hatch) will occur early next week in Henderson County and at similar elevations. With low codling moth populations, which is the case in many orchards, an initial insecticide application can be delayed until about 350 DD (predicted to occur on May 9 in Henderson County).

In orchards using mating disruption for codling moth, a single insecticide application for first generation codling moth is usually sufficient, and ideal timing is to coincide with TABM control, which occurs at the second or third cover spray.

For insecticide resistance management purposes, do not use insecticides from the same MOA group (see table below) against both the first and second codling moth generation. The second generation will occur in July.

San Jose Scale (SJS): For those growers targeting crawlers, an insecticide targeting this insect should be applied within the next week. The most highly rated insecticides for SJS are Esteem, Centaur, and Movento. Due to insecticide resistance concerns, do not rely on the same insecticide in consecutive years; instead rotate products with different modes of action on an annual basis. Assail also has good activity against SJS, which will further benefit scale control if used over the next several weeks. It should be noted that Esteem and Assail both have activity against codling moth, with Esteem being a good ovicide and Assail providing suppression of adults and larvae.

European Red Mite (ERM): For those choosing a preventive management program for ERM, options include Agri-Mek, Apollo, Savey, Envidor and Zeal. Agri-Mek needs to be applied no later than 1^st Cover, and ideally at petal fall. The remaining products should be applied at or shortly between 1^st and 2^nd cover, and/or before mites increase to 1 or 2 mites per leaf. Again, resistance development is a concern when relying on the same mode of action in consecutive years, so it is strongly recommended to rotate products with different mode of actions on an annual basis (see table below).

Learn more about southeastern apple insect pests at the Apple Insect Management page.

2024 Average Weekly Trap Captures

*Note that these averages illustrate only the timing of insect emergence and fluctuations in populations, and are not representative of population levels in any given orchard. The only way to have an accurate assessment of an individual orchard’s populations is to set up traps in that orchard.

2024 Accumulated Degree Days

About degree-day models

April 8, 2024

Learn more about southeastern apple insect pests at the Apple Insect Management page.

2024 Average Weekly Trap Captures

*Note that these averages illustrate only the timing of insect emergence and fluctuations in populations, and are not representative of population levels in any given orchard. The only way to have an accurate assessment of an individual orchard’s populations is to set up traps in that orchard.

March 25, 2024

Learn more about southeastern apple insect pests at the Apple Insect Management page.

March 18, 2024

Learn more about southeastern apple insect pests at the Apple Insect Management page.