Peach:

Oriental Fruit Moth: We are still between 1^st and 2^nd generations at the present time. Growers that have utilized mating disruption for OFM should continue to focus on PC; GPA; and catfacing insect pests as described below.

Second generation timings will be in about two weeks in southern counties. Overall the adult population is low, but above the treatment threshold of 8 moths per trap on some farms in northern counties.

Plum Curculio (PC): Based on the model developed by Cornell and field observations, we are past peak oviposition in all regions. Therefore the main insecticide targets are now cat facing insects and scale.

Green Peach Aphids (GPA): Scouting has shown that GPA is not a problem in most orchards. If aphids are at treatment level, and your ground cover is clean of blooming weeds, a good choice that will cover catfacing insects, aphids, and plum curculio stragglers is Thiamethoxam (Actara and in VoliamFlexi). Actara will not control OFM. Examine trees for the presence of colonies by standing back and looking at the entire tree. Clusters of curled leaves will define a single colony. Count the number of colonies on ten trees and use a treatment threshold of 2 colonies/tree at petal fall to shuck split for peach, and 1 colony/tree for nectarine. If treating aphids alone then Movento @ 6 oz/A is a good non-neonicotinoid choice. Movento must be combined with a spreader/penetrant spray adjuvant. Used later during late May to early June this will also control scale. Movento will not control PC or catfacing insects. Additional choices include Closer (also effective for scale), Belay, Closer, Cormoran, Versys, and Leverage. See the 2021-22 Tree Fruit Production Guide pp168-169 for a complete list. Lannate can also be used, but is not quite as effective.

Tarnished Plant Bugs and Other Catfacing Insects:  This is the other key insect complex at this time of year. BMSB and native Stink bugs have been found at low levels in beating tray samples, and native stink bug egg masses have been observed in peaches. Tarnished plant bugs will become more of an issue as temperatures warm and mowing and other ground cover activities become more common.

Scale Insects: White peach scale (WPS) crawlers should have emerged in southern counties. San Jose scale (SJS) crawlers usually begin emergence in late May/Early June. If you have scale infestations on your trees, it is important to note if crawlers are present, even if you treated with oil in the early spring. See last newsletter and the 2021 Tree Fruit Production Guide for control options.

Bacterial Spot: Maintain tight covers with antibiotics until pit hardening. Typical antibiotics used include various copper and oxytetracycline formulations. Full covers with at least 100 gpa are recommended around wetting periods or severe weather. No bacterial spot cankers or leaf symptoms have been observed in southern county orchards as of yet.

Peach Scab: In addition to Rusty Spot and Bacterial Spot, peach scab requires protective applications starting at petal fall. Peach scab cankers begin to expand at bloom and by shuck split begin to shed spores during wetting periods. Topsin, Topsin/Captan combinations, Flint Extra, Inspire Super, and especially Quadris Top applied at petal fall are the best materials for blocks that had scab last year. Quadris Top, Flint Extra and Topsin should be used at the high rate to suppress overwintering lesions on the wood. Quadris Top contains azoxystrobin which is phytotoxic to many apple varieties. Phytotoxic residues can remain in the tank for long periods after an application is made, even if a tank cleaner is used. Do not use Quadris Top or Abound in the same sprayer used for apples. Bravo (chlorothalonil) is also a good protectant that may be applied no later than shuck split. Captan is also helpful in cover sprays after shuck split where scab was troublesome last year. Maintain effective scab materials in cover sprays through June.

Rusty Spot: Rusty spot symptoms continue to appear, and infections are ongoing until pit hardening. If you are using Flint Extra, Inspire Super, or Quadris Top for scab, these materials will also control rusty spot. After petal fall, maintain coverage with effective materials such as Rally, Rhyme, or potassium bicarbonate products.

Cherry:

Spotted Wing Drosophila (SWD): Looking ahead, as cherries start to color they will be susceptible to SWD infestation. Effective insecticides for use on cherries include Asana, Baythroid, Cormoran, Danitol, Delegate, Entrust, Exirel, Imidan, Lambda-Cy/Warrior, Mustang Maxx, Malathion, and Verdepryn. Check the 2012 Tree Fruit Production Guide for PHI’s and REI’s for U-Pick operations. See accompanying article; “2021 ranking of insecticides for their performance against spotted-wing Drosophila.” Note that many insecticides that may be registered for a specific crop may not be effective for SWD control. It is generally best to stay with products that are rated “good to excellent” for control, unless specific circumstances merit the use of another product, or used in rotations with “good to excellent” rated products.

Apple:

Codling Moth (CM): The second application is due later this week if using diamides and by June 9 if using other materials. See the chart below for timings based on location and the chemistry being used.

Tufted Apple Budmoth (TABM): If trap counts are high, or above 40 moths per trap, we are considering this to be a high population. If your farm continues to experience high populations, then 4 alternate middle applications of insecticides during June should control the first of 2 generations. While this has been considered a minor pest in recent years, our trap counts show increased activity. With the exception of Assail and other sucking insect materials, and granulosis virus formulations (e.g. Madex), most materials used for Codling Moth will control TABM.

Diseases: Apple Scab, Powdery Mildew, Cedar Apple Rust, and Summer Diseases are diseases of concern at this time.

Apple Scab: The primary scab infection periods are now done for the season. However, we have seen a number of orchards where primary infections got through and scab lesions are developing on the leaves. As these sporulate and additional infection periods occur, these leaves will provide an inoculum source for secondary infections. In conversations with Dr, Norm Lalancette, there are several choices to help deactivate or ‘burn out’ the inoculum on these leaves and protect the developing fruit.

Choice 1 – Topsin-M .75-1 lb/A plus 3-4 lb/Captan 80W

Choice 2 – Use a DMI (FRAC Grp 3) systemic fungicide combined with Captan: Captan + Inspire Super (cyprodinil (Grp 9) + difenoconazole (Grp 3)), or Captan +  Cevya (mefentrifluconazole (Grp 3))

Use at least 2 applications back to back 7 days apart, without precipitation wash-off.

After this, a tight summer disease program that incorporates Captan + ProPhyte,  rotated with Merivon or Luna Sensation, should also control any scab infections.

Powdery Mildew: Mildew infections are still present. Effective materials at this time include Inspire Super, Merivon and Luna Sensation. See the NJ Tree Fruit Production guide for rates and efficacies.

Cedar apple rust infections can occur anytime between pink and 3^rd cover. Symptoms from early infections are present in southern counties. Summer diseases such as rots and sooty botch are beginning to overlap with early season diseases. Most scab materials will control summer diseases (see above on apple scab)

Bitter Pit: Growers who have had trouble with bitter rot may wish to include a phosphonate product (e.g. pro-phyt) with captan. Phosphonates contain potassium and my contribute to bitter pit so avoid the use of phosphonates on Honeycrisp until after cell division is complete, usually sometime after the thinning window has closed.

Grapes:

Diseases: Grape diseases active at this growth stage are phomopsis, powdery mildew and black rot (black rot leaf lesion and phomopsis cane lesion pictured, photo D. Schmitt). Phomopsis and black rot symptoms are present in southern counties. As we approach bloom botrytis will also be a target. Disease infection periods can be monitored using the NEWA models. Growers should monitor potential Powdery Mildew infection periods as the current weather pattern is very favorable for this disease. Choose the weather station closest to your vineyard.

Phomopsis on grape cane. (Photo – D. Schmitt)

Black rot leaf lesion on grape (Photo – D. Schmitt)

Insects: Leafhoppers have been seen in a few spots. This complex is generally not of concern. Potato leafhoppers, which arrive sometime in June, can cause some minor damage. Spotted Lantern Fly nymphs are now hatching in southern counties. These nymphs do little damage and generally don’t need special treatments when present. Even so, vineyards should be monitored for SLF presence and if they are found use an insecticide effective for SLF when treating for Grape Berry Moth in late June.

Grape Berry Moth (GBM): The biofix in southern counties for GBM was  5/20. Model timing will predict IGR and diamide materials for the second generation. The first generation is not really important in cultivated grapes, but is starting now in wild grapes, with some adults starting to come into vineyards. Timing for the second generation treatments is set at 810 degree days base 47⁰F. Given the current weather patterns, this should be about June 24 – 28 in southern counties.

Scouting Calendar Tree Fruit Southern Counties

The following table is intended as an aid for orchard scouting. I t should not be used to time pesticide applications. Median dates for pest events and crop phenology are displayed. These dates are compiled from observations made since 1995 in Gloucester County. Events in northern New Jersey should occur 7-10 days later.

Tree  Fruit Trap Counts – Southern Counties

Tree  Fruit Trap Counts – Northern Counties

Blueberries:

Plum Curculio: During this past week PC berry damage (infested fruit) averaged .13 berries per bush with a high of 3.7 per bush. This is down from the previous week which averaged 0.80 damage berries per bush with a high of 9.8. The decrease is due to the steady drop of infested fruit. Hopefully this will be 0” by the time the first fruit is picked, but there may be some present where the counts are the highest.

Aphids: Aphid colonies continue to increase except in areas that have been recently treated with effective insecticides. The average rate of new shoot infestation averaged 12% of shoots infested with a high of 58% of shoots infested. The average represents almost a 100% increase since the previous week. Given the presence of Scorch virus, it is very important to control aphids, which transmit the disease. Aphids should ideally be controlled BEFORE you need to start concentrating on SWD, since most aphid control materials do not work for SWD and visa-versa. A number of growers have used Brigade and other pyrethroids for aphid control. In most cases, this WILL NOT WORK. We continue to recommend the list of materials that have the greatest efficacy on aphids. These include the neonicotinoids (IRAC group 4A) – Actara, Assail, and Admire, and the new group 4D material, Sivanto. Senstar is a new premix, effective for aphids with the same ingredients that are in Movento and Esteem. We are also looking at Movento (group 23), since it is highly systemic, and may be able to better move to the bottom of the plant where most of the aphids are located. Initial observations with Sivanto show that it has been highly effective, although slow to actually kill the insects, although feeding stops rapidly after application. Exirel has also controlled aphids in research tests. This is mentioned here since this is the last time for a shot at aphid control alone. The next insecticides will also have to start targeting spotted wing drosophila (SWD).

Spotted Wing Drosophila (SWD): SWD adults were captured during the last week of May in the Hammonton area. We suspect that they have been around for a while, but this demonstrates that SWD will be a major pest as fruit starts to color. The strongest insecticides for SWD control are the pyrethroids (Grp 3A), Imidan & malathion (Grp 1B), Lannate (Grp 1A), Delegate & Entrust (Grp 5), Exirel and Verdepryn (Grp 28), and the premix Cormoran (acetamiprid + novaluron)(Grp 4A+15). Please see the accompanying article on SWD insecticide rankings. Assail will give some control, but only on very low populations. Exirel will give some aphid control and is very good for SWD. Lannate will ‘suppress’ aphids, and is also a good SWD material. The other insecticides listed here should be considered primarily SWD materials that also control blueberry maggot (BBM). Delegate and Entrust are weaker on BBM. Please the accompanying article on SWD insecticide rankings, compiled by Phil Fanning and Rufus Isaacs as part of the USDA/SCRI SWD management project.

The bottom line: If aphids have been controlled then switch to any of the  highly effective SWD materials. If aphids have not been controlled, then use a product like Assail, Cormoran, Exirel or Lannate during the next 4-5 days. After that any aphid control will have to take a back seat to SWD management.

2021 ranking of insecticides for their performance
against spotted-wing Drosophila^[1]

Developed by applied entomologists managing this pest in California, Florida, Georgia, Maine,
Michigan, New Jersey, New York, North Carolina, Oregon, and Washington.

^[1] Compiled by Philip Fanning, School of Biology and Ecology, University of Maine and Rufus Isaacs, Department of Entomology, Michigan State University. Contact philip.fanning@maine.edu with questions about this article.

The invasive spotted-wing Drosophila (SWD) has been a pest of berries and cherries across the United States for the past decade. Since its introduction, insecticides have been an important management tool for this pest, to minimize fruit infestation. Annual field research trials conducted by applied entomologists have identified effective options for chemical control of SWD, but each trial is typically a small subset of the available options. To synthesize the existing research and practical experience on insecticide performance against this pest, rankings for insecticides were provided by applied entomologists and leading industry stakeholders at the end of 2020. Their rankings were based on experiences from replicated research trials and grower management of SWD in their regions. This document summarizes those rankings to provide an overview of insecticide effectiveness against SWD.

We received a total of 19 unique state x crop rankings for insecticides against SWD from CA, OR, WA, MI, ME, NY, NJ, NC, GA, FL and from caneberries, cherries, and blueberries. Each person was asked to provide rankings based on a scoring system of 0 = ineffective, 1 = weak, 2 = fair, 3 = good, and 4 = excellent. The average ranking for each insecticide is provided in Figure 1, with a dashed line to highlight products that are ranked Good-Excellent.

Figure 1. Relative ranking of insecticides for their performance against SWD under field conditions, across multiple crops and different regions of the US in 2020.

This figure can provide guidance in selection of insecticides to control this pest, but final decisions should also be based on whether it is registered for your crop, the pre-harvest interval, the cost, and also its suitability for helping to manage insecticide resistance (see second page).

Selection of insecticides for management of SWD is rarely based on efficacy alone. Due to increasing concerns regarding insecticide resistance in populations of SWD, growers, researchers, and extension personnel need to consider rotation of chemical classes when developing their SWD management programs, in addition to their efficacy. To help in this, we have color coded each insecticide for its chemical class (Figure 2). There are 11 chemical classes listed, plus one insecticide that contains two different classes in a pre-mix formulation.

To use this graph for decision-making, consider which insecticides you plan to use and then check whether they have the same color (chemical class) in this figure. Pyrethroids and organophosphates are the two most common classes in the insecticides with high efficacy, so for example this graph can be used to avoid designing a SWD control program based solely on one of those classes. Rotating among multiple chemical classes is expected to minimize resistance.

Figure 2. Relative ranking of different chemical classes of insecticide for their performance against SWD under field conditions, across all crops and regions in the US in 2020. Different colored bars represent different classes of insecticide. *OMRI approved for use in organic production.

As mentioned above, there are many other considerations when developing effective SWD control, but the information in Figure 2 can help avoid development of resistance through rotating chemical classes in consecutive spray applications. There are also many non-chemical approaches to SWD control including selecting earlier-ripening crops, early harvest, pruning to reduce humidity, physical exclusion with netting, and encouraging biological control. Combining these approaches can help reduce SWD infestation within a comprehensive IPM program.

Always check the label to ensure federal and state registration of insecticides on your crop(s) prior to their use. Follow the restrictions including seasonal limits, re-entry restrictions, and pre-harvest intervals.

This survey was funded in part by the USDA National Institute for Food and Agriculture through

the Specialty Crop Research Initiative (award 2020-51181-32140)