June 29, 2020 VOLUME 29, No. 15 Geneva, NY

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IN THIS ISSUE...INSECTS v Apple maggot management v Japanese beetle v Spotted Wing Drosophila updateDISEASES v Fire blight survey 2020 FAQsCHEM NEWS v Spear-Lep Inscalis insecticide labeled v Mustang Maxx 24(c) 3-day PHI in cherriesTRAP CATCHESMODEL BUILDING UPCOMING PEST EVENTS

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scaffoldsF R U I T J O U R N A L

Update on Pest Managementand Crop Development

first 7–10 days of their adult life feeding on substances such as aphid honeydew

until they are sexually mature. Be-cause honeydew is most likely to be found on foliage, and because the flies see the yellow panel as a "su-per leaf", they are naturally attracted

to it during this early adult stage. A few of these panels hung in such an or-

chard can serve as an early warning device for growers if there is a likely AM emergence site nearby.

Many flies pass this period outside of the or-chard, however, and then begin searching for fruit only when they are ready to mate and lay eggs. That means that growers don't always have the advantage of this advance warning, in which case the catch of a single (usually sexually mature) fly indicates that a spray is necessary immediately to adequately protect the fruit. This can translate into an undesirable risk if the traps are not being

FOLLOW THE RED BALL(Art Agnello, Entomology Geneva; ama4@

cornell.edu)

vv This is the time of year to expect the first appearance of apple maggot (AM) flies in wild apple trees and abandoned orchards, which begins first in east-ern NY; Peter Jentsch reported their first capture on June 22 at the Hudson Valley Research Lab. Western NY is generally about a week later, de-pending on what kind of temperatures and rain-fall we get, but so far none have been capture in Geneva. Crop scouts and consultants have used traps to monitor AM populations for many years, but this approach, useful as it is, may not necessarily be recommended in all cases. Some orchards have such high or such low AM pop-ulations that monitoring for them is not always time-efficient. That is, in some blocks, sprays are necessary every season, often on a calen-dar basis; however, in some blocks the popula-tions are so low that they are rarely needed at all. However, most commercial NY orchards have moderate or variable pressure from this pest, and in these cases monitoring to determine when potentially damaging numbers of them are present allows growers to apply only the number of sprays necessary to protect the fruit from infestation.

Sticky yellow panels were some of the first traps for AM, and have been in use for over 70 years; these can be very helpful in determining when AM flies are present. The insects emerge from their hibernation sites in the soil from mid-June to early July in New York, and spend the

HANGTIME

I N S E C T S

scaffolds No. 15 June 29, 2020

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scaffoldsis published weekly from March to September by Cornell University—Cornell AgriTech at the NYS Agricultural Ex-periment Station (Geneva) and Ithaca—with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 2 pm Monday to:

scaffolds FRUIT JOURNAL Dept. of Entomology Cornell AgriTech at NYSAES 15 Castle Creek Dr. Geneva, NY 14456-1371 Phone: 315-787-2341 FAX: 315-787-2326 E-mail: ama4@cornell.edu

Editor: Art Agnello

This newsletter available online at: http://www.scaffolds.entomology.cornell.edu/

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checked daily and are used to signal an immedi-ate response, something that's not always possible during a busy summer.

To regain this time advantage, more effective traps have been developed, which are in the form of a "super apple" — large, round, deep red, and often accompanied by the scent of a ripe apple — in an attempt to catch that first AM fly in the or-chard. Because this kind of trap is so much more efficient at detecting AM flies when they are still at relatively low levels in the orchard, the traps can usually be checked twice a week to allow a 1–2-day response period (before spraying) after a catch is recorded, without incurring any risk to the fruit. Research done in Geneva over a num-ber of years indicates that these traps work so well that it is possible to use a higher threshold than the old "1 fly and spray" guidelines recommended for the panel traps. Specifically, it has been found that sphere-type traps baited with a lure that emits apple volatiles attracts AM flies so efficiently that an insecticide cover spray is not required until a threshold of 5 flies per trap is reached.

The recommended practice is to hang three vol-atile-baited sphere traps in a 10- to 15-acre or-chard, on the outside row facing the most proba-ble direction of AM migration (towards woods or abandoned apple trees, or else on the south-facing side). Then, the traps are periodically checked to get a total number of flies caught; dividing this by 3 gives the average catch per trap, and a spray is advised when the result is 5 or more. Be sure you know how to distinguish AM flies from others that will be collected by the inviting-looking sphere. There are good photos for identifying the adults on the Apple Maggot IPM Fact Sheet; check the web version at: http://hdl.handle.net/1813/43071

In home apple plantings, it is theoretically possible to use these traps to "trap out" local pop-ulations of AM flies by attracting any adult female in the tree's vicinity to the sticky surface of the red sphere before it can lay eggs in the fruit. Research done in Massachusetts suggests that this strategy can protect the fruit moderately well if one trap is used for every 100–150 apples normally pro-duced by the tree (i.e., a maximum of three to four traps per tree in most cases), a density that makes this strategy fairly impractical on the commercial level.

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scaffolds No. 15 June 29, 2020

A variety of traps and lures are currently available from commercial suppliers; among them: permanent sphere traps made of wood or stiff plastic, disposable sphere traps made of flex-ible plastic, and sphere-plus-panel ("Ladd") traps. The disposable traps are cheaper than the others, of course, but only last one season. Ladd traps are very effective at catching flies, but are harder to keep clean, and have performed no better than any other sphere trap in our field tests. Brush-on stickem is available to facilitate trap setup in the orchard. Apple volatile lures are available for use in combination with any of these traps. These tools are available from a number of orchard pest monitoring suppliers, among them: • Gempler's Inc., 100 Countryside Dr., PO Box 328, Belleville, WI 53508; 1-800-382-8473, Fax, 1-800-551-1128 https://gemplers.com/collections/pest-insect-con-trol-insect-traps/products/apple-maggot-fly-dis-posable-red-sphere-trap-kit • Great Lakes IPM, 10220 Church Rd. NE, Vestaburg, MI 48891; 800-235-0285, Fax 989-268-5311 https://www.greatlakesipm.com/mon-itoring/traps/olson/glol220000-olson-red-ball-traps-disposable-100cs • Ladd Research Industries Inc., 83 Holly Court, Williston, VT 05495; 800-451-3406, Fax 802-660-8859 https://www.laddresearch.com/apple-maggot-fly-trap-kit

By preparing now for the apple maggot sea-son, you can simplify the decisions required to get your apples through the summer in good shape for harvest. vv

Japanese Beetle This perennial pest overwinters as a partially grown grub in the soil below the frost line. In the spring, the grub resumes feeding, primarily on the roots of grasses, and then pupates near the soil surface. Adults normally begin to emerge during the first week of July in upstate N.Y., and are no-ticeable in many area orchards now. The adults fly to any of 300 species of trees and shrubs to

feed; upon emergence, they usually feed on the foliage and flowers of low-growing plants such as roses, grapes, and shrubs, and later on tree foliage. On tree leaves, beetles devour the tissue between the veins, leaving a lacelike skeleton. Severely injured leaves turn brown and often drop. Adults are most active during the warmest parts of the day and prefer to feed on plants that are fully ex-posed to the sun.

Although damage to peaches is most com-monly noted in our area, the fruits of apple, cher-ry, peach and plum trees may also be attacked, all of which have been suffering increasing dam-age from these insects in recent years. Fruits that mature before the beetles are abundant, such as cherries, may escape injury. Ripening or diseased fruit is particularly attractive to the beetles. Pher-omone traps are available and can be hung in the orchard in early July to detect the beetles' pres-ence; these products are generally NOT effective at trapping out the beetles. Fruit and foliage may be protected from damage by spraying an insecti-cide such as Assail, Sevin, Endigo or Besiege (in apple) or Admire Pro, Assail, Sevin, Imidan, En-digo, Exirel, Leverage, Minecto Pro or Besiege (in cherries or peaches) when the first beetles ap-pear.(Information adapted from: Johnson, W.T. & H.H. Lyon. 1988. Insects that feed on trees and shrubs. Cornell Univ. Press.; and Howitt, A.H. 1993. Common tree fruit pests. Mich. State. Univ. Ext. NCR 63.)

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scaffolds No. 15 June 29, 2020

SWD TRAPPING UPDATE(Julie Carroll, NYS IPM Program, Geneva; jec3@cornell.edu)

Tart cherry SWD update - Lake Ontario re-gion SWD still hasn't been caught in 3 orchards – all of them are inland sites. Two additional or-chards were at zero catch this week, "catch not sustained" at one location, which had a single SWD caught last week, and "discontinuous" at the other, which has had alternating weeks of SWD catch. Of the remaining six orchards, four had only a single SWD caught, one had 2 SWD and the other had 3. If SWD has been caught in your orchard, ripening and ripe cherries will be at risk of SWD infestation, even if you've had intervening weeks with zero catch. Remember the MSU IPM approach for tart cherries – monitor for SWD, after one SWD is caught, fruit must be protected when it begins to ripen. If none are ever caught in the orchard that season, SWD is not an issue. This is not the time to relax about SWD man-agement. This is the time to really plan carefully your SWD management strategy. Plan your SWD management strategy: Be wise.· Plan insecticide use so you have materials with lower PHI for use close to harvest.· Rotate active ingredients (IRAC groups) through to harvest for resistance management. · Choose CFF/BCFF/ECFF insecticides that have activity against SWD. · Don't stretch spray intervals, 7 day interval max.· Achieve thorough coverage.· If it rains, reapply (according to label).· Mow the row middles.· Read and follow label recommendations.

Last year we saw a spike in trap catch in mid-July. Catch went from an average of about 1 SWD caught to 86 SWD caught, in one week. This was just as the crop was being harvested. The essential element in preventing infestation in the spray records I analyzed last year was choos-ing insecticides with EXCELLENT activity against SWD at that time.

Refer to the SWD Insecticide Quick Guide for tree fruit and grapes www.hort.cornell.edu/fruit/pdfs/swd/treefruit-grape-insecticides.pdf. Cross-reference this with the Cornell Pest Man-agement Guidelines for Commercial Tree Fruit Production. Select insecticides wisely.

Bookmark online resources• SWD on Cornell Fruit Resources (CFR) fruit.cornell.edu/spottedwing/• SWD Management on CFR fruit.cornell.edu/spottedwing/management/• SWD Insecticide Quick Guide www.hort.cornell.edu/fruit/pdfs/swd/treefruit-grape-insecti-cides.pdf• Cornell Fruit Resources, www.fruit.cornell.edu

MODEL BUILDING

Insect model predictions for Highland[H]/Geneva[G][Source: NEWA Apple Insect Models, http://newa.cornell.edu/index.php?page=apple-in-sects; all DDs are B-E]

Obliquebanded Leafroller development: 25% hatch at 450 DD43, 50% hatch at 630 DD43 after biofix; currently at 582[H] / 423[G].

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scaffolds No. 15 June 29, 2020

FIRE BLIGHT SURVEY 2020 FAQs(Anna Wallis & Kerik Cox, PPPMB, Geneva; aew232@cor-nell.edu & kdc33@cornell.edu)

1 – What is the purpose of the 2020 fire blight survey? The fire blight survey is being conducted as both a service to growers and for research. Like in past years, we are able to diagnose fire blight and evaluate streptomycin resistance, although we currently do not have any funding that direct-ly supports this. Samples are also being used to investigate the distribution of different strains of the pathogen in the region, with support from the NYFVI.

2 – What do samples get tested for? Fire blight samples are first tested to confirm presence of the pathogen Erwinia amylovora. Next, they are evaluated for streptomycin resis-tance phenotype (sensitive or resistant). If found to be resistant, the mechanism of resistance is de-termined using a genetic test. Finally, the strain is determined using a genetic test.

3 – How are the samples tested? When a sample is received, it is assigned a unique number and the information on the sam-ple form is recorded in a master database. This information helps us understand where the plant material came from and factors that may con-tribute to streptomycin resistance phenotype and strain. It also helps us trace the sample back to its location in future years, especially helpful if the sample is discovered to be streptomycin re-sistant. Plant material is kept refrigerated until it is processed, within a day or two. In the lab, it is handled under sterile conditions to avoid contam-ination between samples and by other microor-ganisms. A very small portion of the plant tissue is plated on media that only allows the growth of Erwinia amylovora and a few other bacteria.

Plates are incubated for 2–3 days until the patho-gen begins to grow. It is then re-streaked at least once to obtain a pure culture of the isolated patho-gen. The isolate is also re-streaked on media con-taining streptomycin to evaluate streptomycin re-sistance phenotype. To identify the mechanism of resistance, a genetic test called a PCR is used, which requires specialized equipment and mate-rials, and takes about half a day. Identifying the strain requires similar genetic tests followed by sending samples to a sequencing facility on the Cornell main campus. This process can take a few weeks. However, the sequencing facility is currently closed due to quarantine restrictions, so this part of the sample processing is temporarily on hold. In the meantime, frozen samples are re-tained for future use.

4 – Who is doing the testing? Testing is currently being conducted by Anna Wallis, a PhD student in Kerik Cox's lab and the author of this article. Cornell AgriTech is still under very strict quarantine restrictions. From February until April, only essential work was originally allowed to take place. Some labs are beginning to get approved to perform more ac-tivities. Unfortunately, we are still unable to hire additional personnel to assist with the survey or any of our other lab work. So please be patient!

5 – How soon can I expect to get results? Testing requires growing cultures on petri plates multiple times. With a perfect sample and under the best case scenario, it takes at least a week to complete the process. You can expect to get results in about 10 days. We will contact you directly by phone, email, or through the person that collected the sample from your farm.

Managing fire blight post-infection Based on the number of samples we are re-ceiving from around the state and the region, this continues to be a challenging year for managing fire blight. Materials for managing shoot blight

DISEASES

JUSTTHE

FAQS

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scaffolds No. 15 June 29, 2020

may be scarce if in high demand. If fire blight has been identified in your orchard, we recom-mend the following options for shoot blight management. Please check Cornell Pest Man-agement Guidelines for Commercial Tree Fruit Production for specific rates and timings.

• Growth Regulators: The most effective strat-egy for managing fire blight post-bloom is us-ing the growth regulator prohexadione-calcium (Apogee or Kudos), which shuts down plant growth, preventing movement of the pathogen in the plant.

• Plant Defense Inducers (SAR/ISR prod-ucts): Products that induce natural plant defens-es can be applied preventively as well. These products may take a week to have an effect and should be re-applied approximately every two weeks. Products currently on the market include Regalia (Marrone Bio Innovations), an extract of the plant Reynoutria sachalinensis or giant knotweed, Lifegard (Certis), a strain of Bacillus mycoides, and Actigard (Syngenta), the synthetically derived compound aciben-zolar-S-methyl.

• Coppers: Metallic copper can be applied to reduce surface inoculum, protecting tissues from new infections. Unfortunately, it will not penetrate plant tissue or contact bacteria pres-ent within plant tissue. Therefore, it should be applied preventively to reduce the risk of shoot blight infections. However, there is a high probability of damaging fruit finish when using copper post-bloom.

• No Antibiotics: Streptomycin and Kasuga-mycin should NOT be applied UNLESS there is an immediate risk of shoot blight infection. ONLY apply antibiotics within 24 hours of a storm with driving winds or hail. These trauma events will cause damage to tissue, providing an entry point for the pathogen that may lead to shoot blight. REPEATED APPLICATIONS OF ANTIBIOTICS MAY LEAD TO ANTI-

CHEM

NEWS

BIOTIC RESISTANCE AND SHOULD BE AVOIDED.

[Note: Please see updated Sample Submission Form at the end of this issue.] vv

Spear-Lep (Vestaron, new IRAC Group 32, EPA Reg. No. 88847-6) insecticide has recent-ly been registered in NYS for control of Lepi-doptera in pome and stone fruit. This material, which has the novel active ingredient GS-ome-ga/kappa-Hxtx-Hv1a, a biological peptide, must be tank mixed with a Bacillus thuringiensis (Bt) product. When ingested along with Bt, it func-tions as a central nervous system inhibitor. The label lists target species including codling moth, oriental fruit moth, leafrollers, fruitworms and gypsy moth. It has no impact on bees, other pol-linators, or non-target species; it has a 4 hr REI, 0-day PHI, and is MRL-exempt. Spear-Lep has previously been tested in NY, PA, and MI, and we are currently evaluating it in our field trials in Geneva. It is being sold in a regional exclusive distributorship with Nutrien.

Mustang Maxx (zeta-cypermethrin; FMC, EPA Reg. No. 279-3426) insecticide has been granted a FIFRA 24(c) Special Local Need label with the decreased Pre-harvest Interval of 3 days (down from 14 days) for control of spotted wing drosophila and European cherry fruit fly in NY cherries. The label, which can be found on the DEC Pesticide Portal website, must be in posses-sion of the user at the time of pesticide applica-tion.

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INSECT TRAP CATCHES(Number/Trap)

Geneva, NY Highland, NY 6/22 6/26 6/29 6/15 6/22 6/29Redbanded leafroller 0.0 3.0 12.5 Redbanded leafroller 0.0 13.5 37.0Spotted tentiform leafminer 34.0 50.5 81.0 Spotted tentiform leafminer 195.0 307.5 236.0Oriental fruit moth 0.0 14.5 15.0 Oriental fruit moth 4.5 4.0 6.0Codling moth 13.5 29.0 11.5 Black stem borer 8.5 9.0 10.5Lesser peachtree borer 7.0 8.5 6.5 Lesser appleworm 7.0 5.5 – Dogwood borer 1.5 5.5 8.0 Codling moth 18.0 20.5 19.5Peachtree borer 3.0 5.0 6.5 Tufted apple budmoth 11.5 12.5 35.0Obliquebanded leafroller 0.0 0.0 0.0 San Jose scale 0.0 0.0 0.0 Lesser peachtree borer 5.5* 11.5 9.0 Brown Marmorated Stink Bug 1.0 1.0 0.0 6/10 6/17 6/24 Fruit Tree Leafroller 0.0 0.0 0.0Black stem borer 20.0 1.7 31.7 Variegated Leafroller 2.5 0.0 1.5 Dogwood Borer 6.0 6.0 7.0 Sparganothis Fruitworm 0.0 0.5 0.0 Obliquebanded Leafroller 13.5 17.0 12.0 Spotted wing drosophila 5.0* 8.5 14.0 Apple maggot – 2.0* 4.0

*firstcatch

Crist Orchards, Clintondale [photo: P. Jentsch]

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NOTE: Every effort has been made to provide correct, complete and up-to-date pesticide recommendations. Nevertheless, changes in pesticide regulations occur constantly, and human errors are possible. These recommendations are not a substitute for pesticide labelling. Please read the label before applying any pesticide.This material is based upon work supported by Smith Lever funds from the Cooperative State Research, Education, and Extension Service,U.S.DepartmentofAgriculture.Anyopinions,findings,conclusions,orrecommendationsexpressedinthispublicationarethoseoftheauthor(s)anddonotnecessarilyreflecttheviewoftheU.S.DepartmentofAgriculture.

UPCOMING PEST EVENTS

43°F 45°F 50°FCurrent DD* accumulations (Geneva 1/1–6/29): 1274.3 1127.5 819.6 (Geneva 1/1–6/29/2019): 1151.8 1007.0 683.3 (Geneva "Normal"): 1231.5 1239.4 781.2 (Geneva 1/1-7/6, predicted): 1463.3 1302.5 959.6 (Highland 1/1–6/29): 1553.4 989.6 Upcoming Pest Events (Geneva): Ranges (Normal ± StDev):American plum borer 1st flight subsides 1200-1488 745-967Apple maggot 1st catch 122-1762 768-1152Codling moth 1st flight subsides 1293-1828 822-1203Comstock mealybug 1st adult catch 1308-1554 809-1015Dogwood borer flight peak 1415-1847 886-1221Lesser appleworm 1st flight subsides 1002-1538 613-989Lesser appleworm 2nd flight starts 1429-2108 924-1405Lesser peachtree borer flight peak 809-1734 479-1144Obliquebanded leafroller summer larvae hatch 1038-1460 625-957Oriental fruit moth 2nd flight starts 1228-1489 1052-1324 753-965Peachtree borer flight peak 1085-2014 662-1363Redbanded leafroller 2nd flight starts 1196-1547 733-1005Spotted tentiform leafminer 2nd flight peak 1367-1774 854-1179*all DDs Baskerville-Emin, B.E.

Where is fire blight in New York & New England?

Submit fire blight infected trees and strikes for testing Samples are tested for fire blight bacteria, streptomycin resistance, and strain.

Contact one of the persons below to help you collect samples and take data:

Kerik Cox, 315-787-2401, kdc33@cornell.edu, NYSAES (Receiving lab) Janet van Zoeren, 585-797-8368, jev67@cornell.edu CCE LOFT, Orleans Office Dan Donahue, 518-322-7812, djd13@cornell.edu, CCE ENYCHP, Hudson Valley Lab Mike Basedow, 518-410-6823, mrb254@cornell.edu, CCE ENYCHP, Champlain Valley

Samples should be mailed to:

Kerik Cox Cornell AgriTech 15 Castle Creek Dr. Geneva, NY 14456

Sample information

Collector

Name _________________________

Phone _________________________

Email _________________________

Grower □ Same as Collector

Name _________________________

Phone _________________________

Email _________________________

Sample Date

Cultivar

Rootstock

Location

Farm Name ____________________________________________

Block Name ____________________________________________

Street Address ____________________________________________

City, State ____________________________________________

County ____________________________________________

GPS Coordinates _________________________________________

Planting

Year planted ______________ or

Relative age: □ newly planted □ 5-20 years old □ >20 years old

System: □ high density □ semi-dwarf □ old standard

Instructions: It is only possible to isolate the bacteria (Erwinia amylovora) from fresh, active lesions, where healthy tissue meets the diseased tissue. i.e. the lesion margin. Sampling the Lesion Margin Collect samples that include about 3 inches of healthy tissue beyond the infected tissue, and include about 3 inches of infected tissue. Do not submit all the dead branch of the strike, this is often too long and can be cut back, as described. Do not collect entire branches or trees unless symptoms are unusual. Protect samples from drying out prior to submitting them. If possible, refrigerate them. It is impossible to isolate fire blight bacteria from dead, dried out tissue. If possible collect samples with visible ooze!

Fire blight strike on current shoot (photo courtesy of J. Carroll).

Optimal amount of plant material to collect (photo courtesy of A. Wallis).

Lower lesion margin. Cut at least three inches

into healthy tissue, below the lesion.

Healthy growth. Trim this down, leaving about three inches of healthy tissue.

The strike. Cut this back, leaving about three

inches of infected tissue.