WNC Orchard Insect Pest Update - July 22, 2026 - Southern Appalachian Apples

WNC Orchard Insect Pest Update - July 22, 2026

— Written by Jim Walgenbach — Contributors: Stephen Schoof | July 22, 2026 (Updated: July 27, 2026, 1:03 p.m.)

Not much has changed in the past week with regards to pest activity throughout the region. In Henderson County and similar elevations, the codling moth degree-day (DD) model predicts that about 90% of second generation moths have emerged and egg hatch is about 55% complete. In lower elevation orchards the model predicts that third generation moths are beginning to emerge. However, if no damage has been observed by either generation up to this point in time, it is highly unlikely that codling moth will develop into a problem this late in the season.

Yesterday we conducted a survey in apple orchards across Henderson County, and apples in all orchards looked very clean with only some minor damage from early season plum curculio. Woolly apple aphid (WAA) was the most common pest observed, but significant numbers were detected only in orchards sprayed with two applications of Zivalgo against first generation codling moth, as shown in the figure below. Numbers were very low both in orchards not sprayed with Zivalgo or in orchards that received only one application. Even in those orchards that had relatively high numbers of WAA, they were not high enough to warrant insecticide sprays. Parasitized aphids were observed in all orchards.

Chart showing woolly apple aphid populations significantly higher in orchards receiving 2 sprays of Zivalgo versus orchards receiving 0 or 1 spray

Brown marmorated stink bug (BMSB) degree-day accumulations were at 679 in Henderson County and 882 in Cleveland County. The phenology model predicts that about 35% of first generation adults have emerged in Cleveland County, while initial adult emergence (at 743 DD) is predicted in Henderson County for August 1. Up to this point in time BMSB pheromone trap captures have been very low in commercial orchards, which continues the trend of declining populations observed during the past three years. We’ll continue to monitor populations through September.

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 15	Jun 22	Jun 29	Jul 6	Jul 13	Jul 20
Codling moth	0.5	0.0	1.0	3.0	4.5	3.0
Oriental fruit moth	0.5	5.5	4.0	6.5	4.0	7.5
Tufted apple bud moth	0.0	1.0	0.0	0.0	1.0	0.0
Redbanded leafroller	0.0	0.0	1.0	3.0	5.0	1.0
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	1.0
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	12.5	6.5	7.5
Brown marmorated stink bug (commercial)	0.1	0.2	0.2	0.4	1.2	0.8
Brown marmorated stink bug (unsprayed/research)	1.0	0.5	0.0	2.0	1.5	6.0
Spotted tentiform leafminer	0.0	0.0	0.0	0.0	0.0	4.0
Dogwood borer	23.0	56.0	22.0	41.0	33.0	37.0
Peachtree borer	5.0	24.0	21.0	24.0	22.0	20.0
Lesser peachtree borer	27.0	23.0	8.0	13.0	7.0	2.0
San Jose scale	0.0	125.0	72.5	136.5	47.0	22.5
*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 6	Jul 13	Jul 20
Codling moth (Biofix Apr 11)	1462	1638	1795
Oriental fruit moth (Biofix Mar 21)	2106	2316	2499
Tufted apple bud moth (Biofix Apr 17)	1677	1915	2098

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.