Current Western NC Orchard Pest Populations

We track local insect populations throughout the growing season using a system of traps, temperature-recording devices, and degree-day models. Traps and weather data are checked weekly, with results updated by Wednesday afternoon from April through September. Learn more about southeastern apple pests at the Apple Pest Management page.


Weekly summary

August 22, 2016

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As mentioned last week, codling moth and OFM are a concern primarily in those locations where damage has occurred from previous generations or where there is a history of problems.  Decisions on the need for insecticides should be based on pheromone trap captures in individual orchards.

Brown marmorated stink bug pheromone trap captures and damage are beginning to increase in Henderson County.  Trap captures also remained relatively high in Polk and Lincoln Counties.  Recent research in West Virginia has established a preliminary threshold of 10 cumulative bugs per trap (i.e., weekly trap captures added cumulatively).  Based on this figure, trap captures exceeded this threshold at 5 of our 8 locations this past week.  BMSB damage surveys conducted today (Monday) in Henderson County also picked up a slight increase in damage.  For those growers that experienced damage last year or are concerned about the potential for damage this year, an insecticide should be considered at this time.

Insecticides recommended in the table below are limited to pyrethroids and neonicotinoids, and only those materials with pre-harvest intervals (PHI) of 21 days or less are listed.  The pyrethroids generally have longer residual activity than neonics.  Applications should be made at a minimum of 14-day intervals, and under high pressure no longer than 10 days.  On late-maturing cultivars such as Granny Smith and Pink Lady, control through at least mid-September may be necessary.  Note the PHI of various products to avoid applying materials too close to harvest.

See the Pest Update for the week of August 8 for a discussion of the need for stink bug control on apples destined for various markets.

Insecticides Recommended for Late-Season BMSB on Apples
Common name Trade name Amount/acre PHI (days)
Pyrethroids
bifenthrin Brigade 2EC 9.0 fl oz 14
Brigade WSB 22.4 oz 14
Bifenture 2EC 9.0 fl oz 14
Bifenture DF 22.4 oz 14
fenpropathin Danitol 2.4EC 16.0 fl oz 14
lambda-cyhalothrin Warrior II 2.56 fl oz 21
various generics 1EC 5.21 fl oz 21
gamma-cyhalothrin Proaxis 0.5EC 5.21 fl oz 14
beta-cyfluthrin Baythroid XL 2.4 fl oz 7
cyfluthrin Tombstone 2EC 2.4 fl oz 7
beta-cyfluthrin + imidacloprid Leverage 360 2.8 fl oz 7
Neonicotinoids
chlothianidin Belay 2.13F 8.0 fl oz 7
dinotefuran Venom 70SG 5.4 oz 3
Scorpion 35SL 9.5 fl oz 3

Archived Pest Reports for 2016


2016 Average Weekly Trap Captures*

HENDERSON COUNTY
Insects per trap
Aug 8
Aug 15
Aug 22
Codling Moth
2.0
1.5
3.5
Oriental Fruit Moth
4.3
4.0
6.0
Tufted Apple Bud Moth
1.0
0.0
0.0
Redbanded Leafroller
0.0
0.0
0.0
Obliquebanded Leafroller
0.0
0.0
0.0
Lesser Appleworm
0.0
1.0
0.0
Apple Maggot
1.0
0.3
2.3
Brown Marmorated Stink Bug
0.0
0.5
1.8
Spotted Tentiform Leafminer
1.0
5.0
0.0
Dogwood Borer
24.0
27.0
47.0
Peachtree Borer
26.0
34.5
34.5
Lesser Peachtree Borer
12.0
28.5
18.5
San Jose Scale
3.5
42.5
189.5
*Note that averages presented here are intended only to illustrate the timing of insect emergence and fluctuations in population activity, and not as general indicators of population levels. Some orchards included in these averages have significantly higher or lower populations than most commercial orchards in the area, resulting in averages that are sometimes skewed from what is typical. The only way to have an accurate assessment of an individual orchard’s populations is to set up traps in that orchard.

2016 Accumulated Degree Days


Henderson County
 Biofix
Aug 8
Aug 15
Aug 22
Codling Moth
April 15
2214
2399
2544
Oriental Fruit Moth
March 21
2940
3160
3335
Tufted Apple Bud Moth
April 20
2670
2890
3065
About degree-day models:The degree day (DD) models predict adult emergence and egg hatch of each generation. They do not predict the intensity of populations, which can be assessed by using pheromone traps. Hence, the models should be used to help gauge the time period when control is most likely needed, and pheromone traps provide information on the need for and frequency of insecticide applications. For full details, read “IPM Practices for Selected Pests” in the Orchard Management Guide.
CODLING MOTH:
  • 1st generation: Egg hatch begins at about 350 DD after biofix and is completed by 1050 DD. The most critical period for insecticidal control is from 350 to about 750 DD.
  • 2nd generation: Egg hatch of the second generation can extend from about 1300 to 2600 DD after biofix, but the most critical period for insecticidal control is 1400 to about 2500 DD.
  • 3rd generation: Adults begin to emerge at about 2500 DD after biofix, but the model is less accurate in predicting late-season populations.
ORIENTAL FRUIT MOTH:
  • 1st generation: Only one insecticide application between 400 and 500 degree days is usually necessary, as 1st generation egg-laying is usually low on apple.
  • 2nd generation: Effective 1st-generation control may eliminate the need for 2nd-generation control. If trap captures remain high, insecticides may be needed around 1100 to 1400 DD.
  • 3rd generation: Insecticide may be needed at 2200 DD after biofix.
  • 4th generation: Overlapping generations late in the season make it difficult to predict when 4th-generation egg hatch begins, but continuous egg-laying can occur from August through October. Use traps to determine the need for further insecticide applications.
 TUFTED APPLE BUD MOTH:
  • 1st generation: One well-timed insecticide application between 800 and 1200 DD after biofix will often eliminate the need for further control of TABM.
  • 2nd generation: Only if trap captures exceed 25 moths per trap by 2600 DD is an insecticide application recommended. NOTE: Insecticides targeting 2nd generation TABM are usually not necessary if 1st generation populations were successfully controlled.

2016 Pest Trends (click to enlarge)

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