WNC Orchard Insect Pest Update - July 29, 2026 - Southern Appalachian Apples

WNC Orchard Insect Pest Update - July 29, 2026

— Written by Jim Walgenbach — Contributors: Stephen Schoof | July 29, 2026 (Updated: July 29, 2026, 1:14 p.m.)

As of July 29, codling moth degree-day (DD) accumulations are at about 2050 in Henderson County, which predicts about 70% egg hatch of the second generation. In Cleveland County and similar elevations, about 2600 DD have accumulated, which predicts egg laying of the third generation. As indicated last week, codling moth is highly unlikely to be a problem this late in the season in orchards that have not had a problem thus far. Preventive insecticide applications are no longer necessary unless damage is present and moths are regularly captured in traps. Applications should be based on pheromone trap captures.

The brown marmorated stink bug (BMSB) phenology model predicts first generation adults to begin emergence at 743 DD, which will occur in Henderson County tomorrow (7/30). This is one of the earliest emergences on record in Henderson County. Total DD accumulations in Cleveland County are currently 954, which coincides with about 50% emergence of adults. It is important to note that the phenology model predicts the timing of adult emergence, not population abundance or the need for insecticidal control. As mentioned in previous posts, BMSB populations and damage have declined considerably in recent years. Trap captures this year have continued to follow the low population trend, but trap captures early next week may provide a better measure of overall population abundance.

If concerned about BMSB, an insecticide is recommended at about 10% emergence (783 DD), which will occur early next week in Henderson County. Pyrethroids provide the best control of BMSB, with bifenthrin most effective. Historically, late-maturing cultivars are most susceptible to BMSB damage, particularly Granny Smith, Fuji and Pink Lady. BMSB has a low preference for cultivars harvested during the month of August, so insecticides targeting these varieties are not necessary.

Apple maggot flies continue to be captured in our traps located near a non-managed orchard, so an insecticide should be considered in orchards located near non-managed orchards.

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

2026 Average Weekly Trap Captures - Henderson County

	Insects per trap
Insect	Jun 22	Jun 29	Jul 6	Jul 13	Jul 20	Jul 27
Codling moth	0.0	1.0	3.0	4.5	3.0	4.5
Oriental fruit moth	5.5	4.0	6.5	4.0	7.5	17.5
Tufted apple bud moth	1.0	0.0	0.0	1.0	0.0	4.0
Redbanded leafroller	0.0	1.0	3.0	5.0	1.0	0.0
Obliquebanded leafroller	0.0	0.0	0.0	0.0	0.0	1.0
Lesser appleworm	0.0	0.0	0.0	0.0	1.0	2.0
Apple maggot (unsprayed/research)	0.0	0.0	0.0	0.0	0.0	0.0
Apple maggot (abandoned orchard)	0.0	0.0	12.5	6.5	7.5	2.0
Brown marmorated stink bug (commercial)	0.2	0.2	0.4	1.2	0.8	0.6
Brown marmorated stink bug (unsprayed/research)	0.5	0.0	2.0	1.5	6.0	5.5
Spotted tentiform leafminer	0.0	0.0	0.0	0.0	4.0	0.0
Dogwood borer	56.0	22.0	41.0	33.0	37.0	43.0
Peachtree borer	24.0	21.0	24.0	22.0	20.0	24.0
Lesser peachtree borer	23.0	8.0	13.0	7.0	2.0	3.0
San Jose scale	125.0	72.5	136.5	47.0	22.5	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.

2026 Degree Days - (MHCRS) Mills River

	Accumulated Degree Days
Insect	Jul 13	Jul 20	Jul 27
Codling moth (Biofix Apr 11)	1638	1795	1965
Oriental fruit moth (Biofix Mar 21)	2316	2499	2704
Tufted apple bud moth (Biofix Apr 17)	1915	2098	2304

About degree-day models

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.