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 Tuesday afternoon from April through September. Learn more about southeastern apple pests at the Apple Pest Management page.


Weekly summary

July 27, 2015

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With the exception of brown marmorated stink bug, overall insect pressure remains low on apples and peaches in the mountains and western piedmont regions of NC.

Codling Moth: In Henderson County, degree-day accumulations since biofix averaged about 1850. This is a period of time when second generation flight is almost complete, but when the potential for egg laying remains a threat in orchards with existing populations. In fact, we did observe an increase in pheromone trap captures in several minimal or non-sprayed orchards during the past week. However, the vast majority of commercial orchards have no evidence of damage and low pheromone trap captures, and decisions about insecticide sprays should be based on pheromone trap captures in individual orchards.

In the piedmont region (Cleveland County), degree-day accumulations since biofix average almost 2500. Decisions regarding the need for insecticide sprays should be based solely on pheromone trap captures, because the model does not accurately predict third generation activity. Pheromone trap captures that average more than 5 moths/trap per week are an indication that a damaging population may exist.

Oriental Fruit Moth: Although this is a time of the year when OFM populations often increase, we have yet not observed increased captures in pheromone traps in our sampling orchards. Despite low populations and very little evidence of damage in either apple or peach orchards, pheromone trapping is especially important in orchards not using mating disruption.

Apple Maggot: To date, evidence suggests that this may be a low-pressure apple maggot year. Peak trap capture is usually around this time of the year, but trap captures in our non-sprayed orchards remain very low.

Brown Marmorated Stink Bug: In the piedmont counties, there are large numbers of first generation adults emerging from wooded areas and infesting adjacent tree fruits and vegetables. These adults are laying eggs and are expected to continue laying eggs at least through the first week of August. Hence, both adult and nymphs will be potential pests for the next 4 to 6 weeks. In higher elevations, such as Buncombe and Henderson county, first generation adults are emerging, but they are just now beginning to lay eggs. The majority of nymphs currently observed are from those eggs laid by overwintered adults.

In crops with BMSB problems, most pyrethroids and several neonicotinoid insecticides provide good control, but frequent application intervals may be necessary under high pressure conditions. Pyrethroids are particularly harmful to biological control programs in pome fruits, so it is important to verify a BMSB problem before initiating a spray program. The following insecticides are recommended for apples and peaches:

Insecticide (a.i.)

Trade names

Apple PHI

Peach PHI

Pyrethroids:

*Bifenthrin
Brigade, Bifenture, Sniper
14
14
Cyfluthrin
Tombstone
7
7
Beta-cyfluthrin
Baythroid
7
7
Lambda-cyhalothrin
Warrior, Karate, LambdaCy
21
14
fenpropathrin
Danitol
14
3
Zeta-cypermethrin
Mustang Maxx
14
14
Gamma-chyalothrin
Proaxis
21
14

Neonicotinoids:

Dinotefuran
Venom, Scorpion
3
3
Thiamethoxam
Actara
35
14

Mixtures:

Lambda-cyhalothrin + Thiamethoxam
Endigo
14
14
*Bifenthrin and dinotefuran are approved for use in NC under a Section 18 label that expires on 10-15-2015.

Average Weekly Trap Captures*

HENDERSON COUNTY
Insects per trap
July 13
July 20
July 27
Codling Moth
4.3
4.7
9.0
Oriental Fruit Moth
8.3
5.3
5.3
Tufted Apple Bud Moth
0.5
1.5
2.0
Redbanded Leafroller
0.5
0.0
0.0
Obliquebanded Leafroller
0.0
0.5
0.5
Lesser Appleworm
5.0
2.0
0.0
Apple Maggot
0.0
2.0
0.5
Brown Marmorated Stink Bug
20.5
0.3
0.0
Spotted Tentiform Leafminer
0.0
0.0
0.0
Dogwood Borer
29.0
48.0
26.0
Peachtree Borer
30.0
47.5
41.0
Lesser Peachtree Borer
20.0
21.0
7.0
San Jose Scale
10005.0
1697.5
2015.0
*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.

Accumulated Degree Days


Henderson County
 Biofix
July 13
July 20
July 27
Codling Moth
April 23
1480
1662
1840
Oriental Fruit Moth
Apr 6
2098
2315
2518
Tufted Apple Bud Moth
April 23
1839
2055
2258
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.

Pest Trends (click to enlarge)

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