WNC Orchard Insect Pest Update - July 16, 2026 - Southern Appalachian Apples

WNC Orchard Insect Pest Update - July 16, 2026

— Written by Jim Walgenbach — Contributors: Stephen Schoof | July 16, 2026 (Updated: July 27, 2026, 1:04 p.m.)

Apple orchard with orange insect trap in the trees

The insect situation is similar to last week, with second generation codling moth being the main concern. There was also an emergence of apple maggot at our abandoned monitoring site during the past week, which follows patterns observed the past few years.

Codling Moth: Degree-day (DD) accumulations are at about 1700 in Henderson County, which coincides with about 70% adult emergence of the second generation and 30% egg hatch. Trap captures have been relatively high in non-managed sites, but remain low in almost all managed orchards where first generation CM was well controlled. The need for insecticide sprays at this point should be based on pheromone trap captures, and if they remain low insecticides can be avoided. If not monitoring for adult activity, it would be safe to apply one more insecticide against the second generation.

In Cleveland County and other lower elevation orchards, the second generation is essentially complete.

Brown Marmorated Stink Bug: First generation adults are now emerging in lower elevation orchards. Cumulative DD are at about 775 in Cleveland County, which coincides with about 10% of adult emergence. The need for insecticidal control of BMSB is questionable considering the decline in populations over the past few years, but if you are concerned about damage now is good timing for an insecticide application. Bifenthrin is considered the best stink bug insecticide.

In Henderson County and other higher elevation orchards, only 592 DD have accumulated as of July 14, and it’ll be at least another two weeks before reaching the 750 DD mark when emergence begins.

Apple Maggot: Fly activity has picked up in Henderson County based on sticky sphere trap captures. However, trap captures remain low in managed orchards where there are essentially no flies. Apple maggot flies can disperse to about a quarter-mile from their point of emergence, but dispersal is affected by many factors, most importantly the availability of fruit in the vicinity of where they emerged. Red sphere traps baited with volatile essence can be used to determine the risk of an infestation. A preventive application of imidacloprid should be considered if an orchard is adjacent to a known source of apple maggot flies and where trapping is not being conducted.

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 8	Jun 15	Jun 22	Jun 29	Jul 6	Jul 13
Codling moth	0.5	0.5	0.0	1.0	3.0	4.5
Oriental fruit moth	2.0	0.5	5.5	4.0	6.5	4.0
Tufted apple bud moth	7.0	0.0	1.0	0.0	0.0	1.0
Redbanded leafroller	1.0	0.0	0.0	1.0	3.0	5.0
Obliquebanded leafroller	0.0	0.0	0.0	0.0	0.0	0.0
Lesser appleworm	0.0	0.0	0.0	0.0	0.0	0.0
Apple maggot (unsprayed/research)	0.0	0.0	0.0	0.0	0.0	0.0
Apple maggot (abandoned orchard)	0.0	0.0	0.0	0.0	12.5	6.5
Brown marmorated stink bug (commercial)	0.3	0.1	0.2	0.2	0.4	1.2
Brown marmorated stink bug (unsprayed/research)	2.0	1.0	0.5	0.0	2.0	1.5
Spotted tentiform leafminer	0.0	0.0	0.0	0.0	0.0	0.0
Dogwood borer	63.0	23.0	56.0	22.0	41.0	33.0
Peachtree borer	15.0	5.0	24.0	21.0	24.0	22.0
Lesser peachtree borer	38.0	27.0	23.0	8.0	13.0	7.0
San Jose scale	0.0	0.0	125.0	72.5	136.5	47.0
*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.

2026 Degree Days - MHCRS (Mills River)

	Accumulated Degree Days
Insect	Jun 29	Jul 6	Jul 13
Codling moth (Biofix Apr 11)	1235	1463	1638
Oriental fruit moth (Biofix Mar 21)	1877	2106	2316
Tufted apple bud moth (Biofix Apr 17)	1476	1677	1915

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.