Weekly Update 8/26/2025

This is the fifteenth post of the 2025 season for the Tree Fruit Pest Monitoring Network. Although we’re no longer reporting weekly on pest activity, monitoring will continue as collaborators are able up to harvest, with blog posts as needed. Look for more detail and regionally specific management recommendations from your local CCE and regional teams.

Weather and Phenology across the state now

Across the state, early apple harvest has begun! In general, harvest dates are slightly behind averages and the 2023 & 2024 seasons, which were very early. The differences are greatest in cooler sites in WNY, near Lake Ontario. In the Hudson Valley, early varieties have begun picking over the past couple of weeks, including Wildfire Gala (approx. 3 weeks ahead of standard gala), Premier Honeycrisp first picks, Pristine, Ginger Gold and other early crab and heirloom varieties. Plum varieties are in full swing, and peaches are nearly finished. In Western NY, Wildfire Gala has been picking the past 2 weeks, Premier Honeycrisp & Zestar began spot picking end of last week and early this week, and early Ginger Gold harvest may begin this week. Testing is beginning now for standard Gala and Mcintosh, with Honeycrisp soon to follow. In the Champlain Valley, Ginger Gold is harvesting and Premier Honeycrisp spot picking now, with more testing for standard varieties next week.

As we near harvest, regional teams have started producing weekly maturity reports. Sign up for these updates for regional and variety-specific information. Comparisons of DD accumulations and seasonal conditions indicate predicted harvest will be slightly later than the last two seasons, particularly in WNY.

The hot dry weather across the state has finally subsided across most of the state.  Over the past two weeks, highs continued to be in the upper 80s in many locations, with high humidity, and little rainfall. The first two weeks of August were very dry, and although some scattered showers were produced across the state, most locations recorded less than 1/2″ of rainfall. This changed around 8/18-20 as a cool front moved across the state bringing rain storms and cooler weather. Some locations recorded 1-1.5″ of precipitation, with the most in the Hudson Valley and Western NY east of Rochester. The Champlain Valley and Western NY west of Rochester missed the center of this weather system, with <1/2″ recorded in most places in Orleans and Niagara counties over the past week, and <1/4″ in most locations in Clinton County.

This week, cooler temperatures are expected to continue. Highs in the Hudson Valley will be in the low 70s, and overnight lows may dip into the upper 40s. Western NY and the Champlain Valley will both likely have highs in the lower 70s or upper 60s. Some scattered rainfall is possible this week. Hot, dry conditions are expected to return over the weekend or early next week, with the next possible rain at the end of next week. Long term forecasts by the NOAA Climate Prediction Center indicate a temperatures and precipitation are likely to be close to average in both the 6-10 and 8-14 day forecasts.

Approximate apple phenological stages recorded in locations across NY State 

Record these biofixes for your orchard!

Phenology & DDs for NY NEWA Stations from 1/1 – 8/27

*all DDs Baskerville-Emin, B.E

Upcoming Pest Events

Fact sheets for tree fruit pests can be found on the Cornell IPM Fact Sheet website. More information on the NEWA Models can be found on the NEWA website and in this NEWA Quick Guide for Apple Insect Pests. 

Diseases

Summer diseases are of primary concern at this time. Symptoms of various fungal diseases are abundant in unmanaged locations, including Black Rot or Frogeye Leaf Spot, White Rot, Bitter Rot, and Sooty Blotch Flyspeck. Black typically begins as round brown lesions on leaves, with a purplish edge. Fruit may also be infected, beginning as small black spots, then encompassing the fruitlet, which will eventually turn into a mummy. White rot does not infect the leaves, fruit infection begin similarly as small spots, but the progress to rot the core of the fruit, and is typically lighter in color and very wet. Both over winter in damaged or diseased woody tissue. Bitter rot causes characteristic lesions on the fruit with concentric rings, and produces orange sporulation. We are observing abundant black rot foliar lesions, and early fruit spots of these rots in low managed orchard in the Hudson Valley, where there has been plenty of opportunity for infection and disease development with all the rainfall. Sooty Blotch and Flyspeck are superficial diseases, causing black to greenish diffuse spots on the surface of the fruit.

Leaf spot symptoms with various biotic and abiotic causes are being observed in many locations across the state. Symptoms may be caused by the pathogens such as Marssonina (apple blotch) and Glomerella (bitter rot), as well as physiological disorders such as necrotic leaf blotch, and other environmental injuries (yellowing due to excessive moisture and/or poor nutrition, chemical injury, and mechanical damage). It is critical to properly diagnose the damage observed to ensure effective management.

For the best disease protection, stay covered leading up to harvest. A traditional, conservative recommendation is to reapply a fungicide cover every 2 weeks or after 1.5-2 inches of rainfall.

Insects

Throughout the season, continue to be checking traps and recording the biofixes for economically significant insects. A biofix is a biological indicator, observed in the field/orchard, used to start model calculations. Many models use a unique biofix, which must be recorded at the particular location of interest. Examples include 50% green tip, first sustained trap capture of moths (e.g. 2 consecutive weeks of adult captures). Specific biofixes used in NEWA can be found online: https://newa.cornell.edu/default–biofix–dates/. 

Apple Maggot has been active for most of July and August. Trap counts are variable, as this can be a sporadic pest. In many locations, trap captures remain well below thresholds for management. But other locations greatly exceed thresholds in July, with trap captures as high as 80-100/trap per week. This insect typically emerges around the end of June in Geneva and starts laying eggs in fruit early in July. Red sphere traps coated with tanglefoot (sticky) and with an apple or pear essence lure should be set at the edges of orchards, especially in area where you have known pressure. Three traps are recommended. Management is recommended when you reach an average of 5 flies per baited trap or 1-2 flies per unbaited trap. Traps should then be cleaned and the counts and thresholds reset.

Stink Bugs, including Brown Marmorated Stink Bug (BMSB) and several native stink bug species all are active at this time. But trap captures are low across the state, indicating lower pressure than previous years. These insects typically move into the orchard from the hedgerows. You can monitor with a tedder (pyramid) trap using the appropriate pheromone lures. For these traps, the management threshold is 10 insects/trap. A clear sticky panel trap with pheromone lures can also be used. Thresholds have not been formally developed, but we recommend a lower threshold, approx. 3-4/week. A 2019 management update can be found here: https://rvpadmin.cce.cornell.edu/uploads/doc_744.pdf  and a 2023 update in the Fruit Quarterly Fall 2024 Issue.

European red mite and Two Spotted Spider Mite infestations have continued to be reported in many regions. The cooler temperatures will slow the development and reduce generations of these insects. Use the diagrams in the Cornell Guidelines for sequential sampling methods and thresholds for management. Now that we are in August, threshold for management is now 7.5 mites/leaf higher than June or July. Make sure to flip leaves over and use magnification to see these tiny insects!

Lepidopteran pests, including OFM, CM, and OBLR, continue to be active but of low concern in most areas. If first and second generation management were successful, this third generation is of low concern. When selecting materials for managing these lepidopteran pests, rotate IRAC groups (Modes of action) for resistance management. Use the same mode of action for a given generation, rotate to a new MoA for the second generation.

Oriental Fruit Moth third generation flight is beginning now in most of the state. Third generation typically begins in Geneva at approximately 2275 DD45 or August 9 +/1 9 days. Throughout the state our trap captures remain low. Use the NEWA OFM Model to forecast when egg hatch will occur and time insecticides. Trap captures have been low in our monitoring network for the past few weeks.

Management timing:

• 170-200 DD 45, hatch of first generation larvae around petal fall
• 1150-1200 DD 45, hatch of second generation (after first gen biofix), approx. late June in Geneva

Obliquebanded Leafroller second generation is active at this time in CV and WNY, and nearly over in the Hudson Valley. This second generation of OBLR is typically observed as this insect prepares to overwinter, with flight beginning in Geneva at approximately 2413 DD43 or approximately Aug. 7 +/- 9 days. This generation overwinters as young larvae, which become active early in the spring prior to bloom. This generation can be scouted for at Tight Cluster in apples, and can be managed with a Bt application where pressure has been high in the previous season. Especially in the Champlain Valley, trap counts were up this week, where there seem to be higher populations of this insect. Consider scouting for larvae this week to see if management is necessary.

Codling Moth second generation is over or tapering across the state. The flight of the second generation in Geneva typically begins around 1887 DD43, of July 20, with peak flight at approximately August 6 +/- 1-2 weeks. Second generation peak flight is past in WNY and the CV. Management is over for the HV.

Management timing for insecticides:

• Insecticides targeting eggs: 150–175 DD 50 after biofix (note, Rimon may only be used once per season in NYS)
• Insecticides targeting hatching larvae: 230–250 DD 50 after biofix
• Follow up 14 days later
• Second Generation larval emergence can be roughly approximated based on first generation: 1250-1300 DD after 1st gen. biofix.

Woolly apple aphid activity continues to be reported in many locations. Populations have begun moving out into the canopy over the past month. Look in axils of leaves, where leaf connects to a new shoot. Make sure to pull aside branches and look inside the canopy where these insects are well protected by the leaves and their woolly covering. There are some natural enemies, including a parasitic wasp that can lay eggs inside aphids, leading to a parasitized black mummy aphid with round exit holes.

Spotted wing drosophila trap captures have continued to be very high throughout the month of August. Once this insect emerges, it is typical for populations of this insect to increase rapidly. It is important to be monitoring in your location because emergence can vary by year, weather, and location. You can also check for fruit infestation by using a salt flotation test for larvae in the fruit. Check the Berry Pest Monitoring Network for updates.

Upcoming Phenology & Pest Events Table

Reference: Table 7.1.4. Degree-day accumulations (from Jan. 1) corresponding to selected fruit phenology and arthropod pest events. Cornell Tree Fruit Guidelines.

Additional Resources

Weather

Northeast Regional Climate Change Monthly Maps
https://www.nrcc.cornell.edu/regional/monthly/monthly.html

NOAA Climate Prediction Center (forecasts and outlooks)
https://www.cpc.ncep.noaa.gov/products/forecasts/

Sunburn

Fruit Quarterly Article on research at the HVRL, also explaining types of sunburn.
https://nyshs.org/wp-content/uploads/2016/10/Reig-Pages-5-10-from-NYFQ-Book-Fall-2016.pdf 

NEWA and Pest Forecasting

NEWA Help Desk Frequently Asked Questions
https://help.nysipm.org/hc/en-us/categories/16994462926231-NEWA-Network-for-Environment-and-Weather-Applications

NEWA Help Desk Apple Insect, Disease, and Crop Management Forecasts
https://help.nysipm.org/hc/en-us/sections/17011505301783-Apple-Insect-Disease-and-Crop-Management-Forecasts

Quick Guide for Apple Insect Pests
https://help.nysipm.org/hc/en-us/articles/23290226665751-NEWA-Quick-Guide-for-Apple-Insect-Pests

Apple IPM Intensive Workshop playlist:
https://www.youtube.com/playlist?list=PLoNb8lODb49vifrm9Tla4GmAVhlIL0527

Apple Insect Targets and IPM Practices (including explanations of Degree Day calculations):
https://youtu.be/NwyBAcvbpUs

Virtual Orchard Scout Training webinar recording on the New York State Integrated Pest Management Program (NYSIPM) YouTube channel.
https://www.youtube.com/watch?v=OtyOWCL1Q2A

Online Course, BF224: Tree Fruit Scouting.
https://smallfarmcourses.com/p/bf-224-tree-fruit-scouting