Weekly Report 6/24/2025

This is the eighth post of the 2025 season for the Tree Fruit Pest Monitoring Network. Each week we’ll provide a short summary of trap captures and pest activity in orchards from across NY State. Look for more detail and regionally specific management recommendations from your local CCE and regional teams.

Weather and Phenology across the state now

In orchards across NY fruit sizing and starting to color. In Highland at the Cornell AgriTech Hudson Valley Research Lab, and commercial orchards in the Hudson Valley most varieties are near 30-35 mm fruitlet diameter as of Monday 6/16. In Western NY, apples are also sizing and the results of thinning are becoming apparent. Despite the long, cool bloom period and marginal pollination conditions, there is an excellent potential crop. Apples, as well as stone fruit are starting to color across the state, with the early cherries picking in the Hudson Valley this week and many operations in their second week for strawberries.

Aside from a few dry days last week, the cool, wet weather trend has continued. Following record rainfall for the month of May across most of the Northeast, many locations received 1-2″ of rain this past week, according to NEWA weather stations. As we approach the solstice this weekend, weather is expected to change dramatically. Much warmer, drier conditions are expect this weekend and early next week, with highs potentially reaching 90F. Much warmer than average weather is predicted in the 6-10 and 8-14 day outlooks according to the NOAA Climate Prediction Center.

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 – 6/23

*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

Fire blight has been observed on commercial farms in regions across NY. The hot conditions this week are ideal for additional infection events. Use the NEWA fire blight model to determine if there is risk in your orchard. Look for wilted flower clusters with blackened fruit petioles (stems) and stuck to the cluster, compared to thinning activity, which turns yellow and falls off the tree. Ooze will also be evident once there are warmer conditions and more bacterial growth.

If you have fire blight on your farm, management now is critical! Prune out strikes as soon as possible, consider an application of prohexadione calcium (Apogee/Kudos). An antibiotic application should be considered if you have a trauma event on your farm which would create wounds in the plant tissue for the bacteria to enter, such as high winds or hail.

Apple Scab lesions are continuing to be found in all regions of the state. Weather conditions now are not ideal for scab, as it prefers cooler weather. It is still critical to be scouting for infections now, to determine if management of secondary infections is necessary for the duration of the season. Look for olive green to brown lesions, on the oldest leaves first, often first appearing on the underside of the leaves. Weather has continued to produce perfect conditions for secondary infections to take place.

Powdery mildew continues to by very active throughout the state. Hot humid conditions, which we are experiencing now, are ideal for rapid development of new infections. Secondary infections are visible as powdery white sporulation on new shoot terminals. New leaves are most susceptible, keep trees protected terminal bud set, typically in July. Check out this article summarizing seasonal powdery mildew recommendations. https://blogs.cornell.edu/enychp/tree-fruit/apples/powdery-mildew-management-review-for-2025/

Summer diseases, including Black Rot or Frogeye Leaf Spot, White Rot, Bitter Rot, and Sooty Blotch Flyspeck complex are also active now in most of the state. 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 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.

Insects

Now is the time of year to be checking traps and recording the first 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/. 

Obliquebanded Leafroller management window is now in most of the state! The heat has compressed insect activity and management in regions across the state. Biofix (first trap capture) was reported in many locations 2-3 weeks ago in most locations. Insecticides targeting larvae at 350 DD43 after the biofix. Biofix in the Hudson Valley Research Lab and in commercial orchards this week, and applications should have been made at the beginning of this week (6/22). In Western NY and the Capital Region, flight began last week and applications targeting larvae will be appropriate at the end of this week. In the Champlain Valley, only very low moth captures have been reported in a few trapping locations.

Apple Maggot activity is expected to begin soon! Now is the time to be setting out traps. 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 fly per unbaited trap. Traps should then be cleaned and the counts and thresholds reset.

Codling Moth is between first and second generation across the state. The flight of the second generation typically begins around 1887 DD43, of July 20 +/- 1-2 weeks in Geneva. When selecting materials for managing codling moth, 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.

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

Oriental Fruit Moth is also between generations. Tunneling and frass has been observed in developing fruitlets in unmanaged blocks in all parts of the state. Use the NEWA OFM Model to forecast when egg hatch will occur and time insecticides. Management typically coincides with petal fall and other insect management at this critical timing. An additional cover is recommended approximately 10-14 days after the petal fall application. Second generation flight of OFM is expected soon in the Hudson Valley.

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

Leafhoppers are also very active this week. There are several types of leafhoppers that can affect tree fruit. Potato leafhopper is most common and problematic. It does not overwinter in the Northeast, but arrives on air currents from the south. They feed on new terminals causing the leaves to curl outward and yellow. Leaf margins eventually turn brown, which is often called ‘hopper burn.’ Look on the underside of terminal leaves for these small light green insects, which will move side to side and may jump quickly off of the leaf.

Dogwood borer trap captures have been reported in many locations across the state. First flight is typically around 963 DD43, which is approximately June 12 in Geneva. In the Hudson Valley, biofix was reported 6/2. Biofix for most locations in Western NY and the Capital Region was last week. These are clear-winged moths with distinctive yellow banding. Flight of the adults and egg hatch lasts for a long period of the season, often up until harvest, making management targeting egg hatch difficult. Mating disruption is a very effective management strategy, now is a good time to be deploying mating disruption dispensers.

Green aphids are active in orchards now. Make sure to flip leaves over to inspect for colonies. Green aphids are typically active on the newest terminal leaves first, also flip leaves over to look for colonies or winged adults.

European red mite and Two Spotted Spider Mite infestations have been reported many regions. The hot dry weather is especially idea for rapid generations of these insects, especially in areas where it is very dusty. Use the diagrams in the Cornell Guidelines for sequential sampling methods and thresholds for management. Now that we are in June, threshold for management is 2.5 leaves with mites present.

Spotted wing drosophila first trap captures have been reported in several counties across the state, including both east and west of Rochester, as well as several locations in Dutchess county in the Hudson Valley. Trap captures remain very low (<5) in most locations and many locations have not reported SWD, although one location did see an increase to 15 this week. Check the Berry Pest Monitoring Network for updates.

Cherry Fruit Flies including several native species and the invasive European Cherry Fruit Fly are active now. Begin management as soon as fruit begins to blush.

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/

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