WNC Orchard Insect Populations – May 21, 2019

— Written By and last updated by

Picture of irrigation pond by apple orchardThe insect situation has not appreciably changed since last week. Codling moth remains the key pest of concern throughout the region. Cumulative degree-days range from about 445 in Henderson County to about 656 in Cleveland County, which indicates we are in the midst of first generation egg laying. Overall, populations have been quite low throughout the area. With unseasonably warm weather forecast for the next few weeks, first generation flight should be completed much sooner than normal;  the main period of activity should be complete in about a week in lower elevations such as Cleveland County, and about two weeks in Henderson County.

The warm spring has also accelerated tufted apple bud moth development, with about 550 DD accumulated since biofix in Henderson County. A single insecticide spray made between about 700 and 1200 DD will provide season-long control of TABM. Insecticides of choice include Altacor, Delegate, and Intrepid, all of which are highly effective against this pest.

Brown marmorated stink bug pheromone trap captures increased this week across the area, increasing from an average of 0.7 last week to 2.0 this week. Whether this increase justifies an insecticide application is debatable. We are currently testing a preliminary threshold level of 4 cumulative bugs per trap, and based on averages across all orchards we are currently at about 3, so from this perspective one may want to wait until next week to see if numbers still increase. The need for BMSB control in orchards this early in the season is unusual. Last year at this time trap captures were slightly higher than now, and damage was minimal despite few insecticide sprays being made.

The anticipated stretch of hot dry weather should make conditions ideal for European red mite outbreaks, so it would be wise to begin scouting at this time. Surprisingly there have been very few aphids or leafhoppers observed to date. However, it is usually late May to early June when these insects appear, so anticipate these pests in the next two weeks.


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


2019 Average Weekly Trap Captures

HENDERSON COUNTY
Insects per trap
May 6
May 13
May 20
Codling Moth 4.0 1.7 2.0
Oriental Fruit Moth 26.3 6.7 2.7
Tufted Apple Bud Moth 37.0 90.0 39.0
Redbanded Leafroller 0.0 0.0 0.0
Obliquebanded Leafroller 0.0 1.0 2.0
Lesser Appleworm 0.0 0.0 0.0
Apple Maggot (abandoned and research)  
Brown Marmorated Stink Bug (commercial – mountains) 1.0 0.6 2.1
Brown Marmorated Stink Bug (commercial – upper Piedmont) 3.3 1.7 1.7
Brown Marmorated Stink Bug (research – unsprayed) 0.5 0.7 1.3
Spotted Tentiform Leafminer 0.0 0.0 0.0
Dogwood Borer 0.0 7.0 4.0
Peachtree Borer 0.0 0.0 0.0
Lesser Peachtree Borer 112.0 21.0 64.0
San Jose Scale 2.5 0.0 0.0

*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.


2019 Accumulated Degree Days

  Henderson County
 Biofix May 7
May 14
May 21
Codling Moth Apr 15 260 377 448
Oriental Fruit Moth Mar 16 632 760 882
Tufted Apple Bud Moth Apr 20 290 417 540

About degree-day models


2019 Pest Trends (click to enlarge)

Insect population trend graph Insect population trend graph Insect population trend graph Insect population trend graph Insect population trend graph Insect population trend graph Insect population trend graph Insect population trend graph Insect population trend graph Insect population trend graph Insect population trend graph Insect population trend graph Insect population trend graph


PREVIOUS UPDATES

May 14, 2019

Codling Moth:  We remain in the timeframe when codling moth is the key insect of concern in apples. Degree-day accumulations since biofix range from about 360 in Henderson County (2100 ft elevation) to about 550 in Cleveland County (850 ft). First generation codling moth can remain active through about 600 to 800 DD, depending on population density. Generally, the higher the population the later activity declines.

In locations of about 2000 ft elevation, 350 DD coincides with the optimum timing for the first of either one or two applications against the first generation. A second application is recommended in another two to three weeks, at which time a spray for tufted apple bud moth is also recommended.

In lower elevations, where DD accumulations average about 550, a final spray for first generation codling moth in orchards with low to moderate populations is recommended at this time. This will also coincide with tufted apple bud moth (TABM) in these locations.

It should be noted that the above are general recommendations for orchards that are not using mating disruption. The number of sprays required will vary depending on the intensity of populations, and the only way to know population intensity is with the use of pheromone traps (See the article from April 10 on pheromone trapping). In some instances only one insecticide spray will be necessary, while in orchards with high populations as many as 3 or 4 applications may be necessary.

As in past years, Altacor and Delegate remain the most effective insecticides against codling moth, and whichever product is used against the first generation should NOT be used against the second generation in July – it is necessary to alternate insecticides against generations. Also, for those orchards with very low codling moth populations and where only one application may be necessary, you may want to consider Intrepid for a second application where TABM control is also necessary,  Intrepid is an excellent product for control of TABM, but should not be relied upon for control of moderate to high codling moth populations.

Brown Marmorated Stink Bug:  Much of the BMSB population has emerged from overwintering sites, and emergence is expected to be complete in the next week or two. To date populations have been relatively low, averaging less than one per trap across the region. Beginning next week we will provide degree-day accumulations for BMSB and estimates of when first generation adult emergence is expected. While things can always change, at this time we do not expect action will be necessary against this pest until July (Piedmont) or August (mountains).


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


2019 Average Weekly Trap Captures

HENDERSON COUNTY
Insects per trap
Apr 29
May 6
May 13
Codling Moth 4.5 4.0 1.7
Oriental Fruit Moth 67.5 26.3 6.7
Tufted Apple Bud Moth 15.0 37.0 90.0
Redbanded Leafroller 1.0 0.0 0.0
Obliquebanded Leafroller 0.0 1.0
Lesser Appleworm 0.0 0.0
Apple Maggot (abandoned and research)  
Brown Marmorated Stink Bug (commercial – mountains) 1.4 1.0 0.6
Brown Marmorated Stink Bug (commercial – upper Piedmont) 3.7 3.3 1.7
Brown Marmorated Stink Bug (research – unsprayed) 1.0 0.5 0.7
Spotted Tentiform Leafminer 0.0 0.0 0.0
Dogwood Borer 0.0 7.0
Peachtree Borer 0.0 0.0 0.0
Lesser Peachtree Borer 58.0 112.0 21.0
San Jose Scale 0.0 2.5 0.0

*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.


2019 Accumulated Degree Days

  Henderson County
 Biofix Apr 29
May 7
May 14
Codling Moth Apr 15 133 260 377
Oriental Fruit Moth Mar 16 466 632 760
Tufted Apple Bud Moth Apr 20 124 290 417

About degree-day models


May 7, 2019

Codling moth adultCodling Moth:  The major insect of concern at this time is the codling moth. Degree-day accumulation in the mountains at about 2100 ft elevation was 260 as of May 6, and in the piedmont at an elevation of 900 ft, it was 400.

In orchards with moderate to high populations of codling moth, first generation egg hatch begins at about 250 DD, so in those orchards an insecticide effective against codling moth should already have been made. In orchards with low populations – i.e., none or very low damage last year and no more than about 2 moths captured in pheromone traps during the past week – waiting until about 350 DD for an initial application is most efficient. In the mountains this is predicted to occur early next week, and in piedmont orchards we are beyond that point.

Remember, the above predictions are for orchards NOT using mating disruption. Where mating disruption is being used for codling moth and OFM, an insecticide is not recommended until tufted apple bud moth cumulative degree days reach 600 to 800.

European Red Mite Sighting:  There have been reports of European red mite showing up on apples this week in Henderson County. In the past 20 years, this is only the second time I am aware of ERM appearing this early in the season. This is unusually early, and probably reflects the more widespread use of pyrethroids in recent years. Hence, in those orchards that did not use a preventive miticide application (e.g., Agri-Mek, Zeal, Apollo, Savey or Envidor), it would be wise to check your most mite-susceptible blocks.


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


2019 Average Weekly Trap Captures

HENDERSON COUNTY
Insects per trap
Apr 22
Apr 29
May 6
Codling Moth 4.0 4.5 4.0
Oriental Fruit Moth 61.0 67.5 26.3
Tufted Apple Bud Moth 3.0 15.0 37.0
Redbanded Leafroller 0.0 1.0 0.0
Obliquebanded Leafroller 0.0
Lesser Appleworm 0.0
Apple Maggot (abandoned and research)
Brown Marmorated Stink Bug (commercial – mountains) 1.4 1.0
Brown Marmorated Stink Bug (commercial – upper Piedmont) 3.7 3.3
Brown Marmorated Stink Bug (research – unsprayed) 0.0 1.0 0.5
Spotted Tentiform Leafminer 0.0 0.0 0.0
Dogwood Borer 0.0
Peachtree Borer 0.0 0.0 0.0
Lesser Peachtree Borer 5.0 58.0 112.0
San Jose Scale 0.0 0.0 2.5

*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.


2019 Accumulated Degree Days

  Henderson County
 Biofix Apr 22
Apr 30
May 7
Codling Moth Apr 15 45 133 260
Oriental Fruit Moth Mar 16 348 466 632
Tufted Apple Bud Moth Apr 20 18 124 290

About degree-day models


April 30, 2019Image of apple orchard

By now petal fall applications have been made in most locations except for the highest elevation orchards (e.g., ≥3000 feet), and attention can now move to other pests – especially the codling moth.

Codling Moth:  Codling moth biofix date in Henderson County (elevation about 2100 ft) occurred on 15 April. Typically biofix occurs about a week earlier off the mountain in Cleveland and Lincoln Counties (about 900ft), and is estimated to have occurred on 8 April. Codling moth egg hatch begins at about 250 cumulative degree days (DD), which is the recommended timing of first insecticide applications in orchards with moderate to high populations. For orchards with low populations, which is the more common situation, the initial timing can be delayed to about 350 DD.

In Henderson County we are currently at about 133 DD, and 250 DD is estimated to occur next Monday (May 6) and 350 DD on May 11. Off the mountain at an elevation of about 900 ft (Cleveland/Lincoln County), we are currently at about 300 DD and 350 is predicted for later this week on Friday or Saturday (May 3 or 4).

In orchards using mating disruption and where pheromone trap captures remain low, insecticides for codling moth are not necessary at this time. In most situations with mating disruption a single insecticide application against the first generation codling moth is not recommended until about 600-700 DD have accumulated, which coincides with the optimum timing of first generation tufted apple bud moth (TABM).

Regarding insecticides recommended for codling moth, they remain Altacor (3 oz/A) and Delegate (6 oz/A). One product should be used for all first-generation applications, and the other product against the second generation in July.

San Jose Scale:  For those that are concerned about San Jose scale and have not yet applied an insecticide effective against this pest, anytime within the next two weeks is ideal timing for application of either Esteem or Centaur, both of which provide excellent control when used at this time.

Another option is use of Movento, which can also provide suppression of woolly apple aphid (WAA) later in the season. The systemic activity of Movento, which is unique in that it moves in both directions in the tree (leaf to leaf, and leaf to roots), is key to preventive control of WAA. It should be noted, however, that WAA is a sporadic pest and often does not develop to pest status. If using Movento, it is important to read the label to ensure proper use. It must be used with an adjuvant with spreading and penetrating properties to maximize leaf uptake for systemic activity. However, DO NOT use Induce, due to compatibility issues.


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


2019 Average Weekly Trap Captures

HENDERSON COUNTY
Insects per trap
Apr 15
Apr 22
Apr 29
Codling Moth 1.5 4.0 4.5
Oriental Fruit Moth 101.5 61.0 67.5
Tufted Apple Bud Moth 3.0 15.0
Redbanded Leafroller 0.0 0.0 1.0
Obliquebanded Leafroller
Lesser Appleworm
Apple Maggot (abandoned and research)
Brown Marmorated Stink Bug (commercial – mountains) 1.4
Brown Marmorated Stink Bug (commercial – upper Piedmont) 3.7
Brown Marmorated Stink Bug (research – unsprayed) 0.2 0.0 1.0
Spotted Tentiform Leafminer n/a 0.0 0.0
Dogwood Borer
Peachtree Borer 0.0 0.0
Lesser Peachtree Borer 5.0 58.0
San Jose Scale 0.0 0.0 0.0

*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.


2019 Accumulated Degree Days

  Henderson County
 Biofix Apr 15
Apr 22
Apr 30
Codling Moth Apr 15 45 133
Oriental Fruit Moth Mar 16 282 348 466
Tufted Apple Bud Moth Apr 20 18 124

About degree-day models


April 23, 2019Apple orchard in spring


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


2019 Average Weekly Trap Captures

HENDERSON COUNTY
Insects per trap
Apr 8 Apr 15
Apr 22
Codling Moth 0.0 1.5 4.0
Oriental Fruit Moth 55.0 101.5 61.0
Tufted Apple Bud Moth 3.0
Redbanded Leafroller 7.0 0.0 0.0
Obliquebanded Leafroller
Lesser Appleworm
Apple Maggot (abandoned and research)
Brown Marmorated Stink Bug (commercial – mountains)
Brown Marmorated Stink Bug (commercial – upper Piedmont)
Brown Marmorated Stink Bug (research – unsprayed) 0.2 0.0
Spotted Tentiform Leafminer 3.0 n/a 0.0
Dogwood Borer
Peachtree Borer 0.0
Lesser Peachtree Borer 5.0
San Jose Scale 0.0 0.0 0.0

*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.


2019 Accumulated Degree Days

  Henderson County
 Biofix Apr 7
Apr 15
Apr 23
Codling Moth Apr 15 45
Oriental Fruit Moth Mar 16 151 282 348
Tufted Apple Bud Moth

About degree-day models


April 16, 2019Bee on apple flower


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


2019 Average Weekly Trap Captures

HENDERSON COUNTY
Insects per trap
Apr 1 Apr 8
Apr 15
Codling Moth 0.0 0.0 1.5
Oriental Fruit Moth 1.0 55.0 101.5
Tufted Apple Bud Moth
Redbanded Leafroller 17.0 7.0 0.0
Obliquebanded Leafroller
Lesser Appleworm
Apple Maggot (abandoned and research)
Brown Marmorated Stink Bug (commercial – mountains)
Brown Marmorated Stink Bug (commercial – upper Piedmont)
Brown Marmorated Stink Bug (research – unsprayed) 0.2
Spotted Tentiform Leafminer 2.0 3.0 n/a
Dogwood Borer
Peachtree Borer
Lesser Peachtree Borer
San Jose Scale 0.0 0.0 0.0

*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.


2019 Accumulated Degree Days

  Henderson County
 Biofix Apr 1
Apr 7
Apr 15
Codling Moth
Oriental Fruit Moth Mar 16 87 151 281.5
Tufted Apple Bud Moth

About degree-day models


April 8, 2019picture of apple blossoms


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


2019 Average Weekly Trap Captures

HENDERSON COUNTY
Insects per trap
Mar 25 Apr 1 Apr 8
Codling Moth set 0.0 0.0
Oriental Fruit Moth 1.0 1.0 55.0
Tufted Apple Bud Moth
Redbanded Leafroller 14.0 17.0 7.0
Obliquebanded Leafroller
Lesser Appleworm
Apple Maggot (abandoned and research)
Brown Marmorated Stink Bug (commercial – mountains)
Brown Marmorated Stink Bug (commercial – upper Piedmont)
Brown Marmorated Stink Bug (research – unsprayed)
Spotted Tentiform Leafminer 0.0 2.0 3.0
Dogwood Borer
Peachtree Borer
Lesser Peachtree Borer
San Jose Scale 0.0 0.0 0.0

*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.


2019 Accumulated Degree Days

  Henderson County
 Biofix Mar 25 Apr 1 Apr 7
Codling Moth
Oriental Fruit Moth Mar 16 41 87 151
Tufted Apple Bud Moth

About degree-day models