2025 Fruit Pest Management Recommendations Posted

Hello, everyone,

This year's revisions to our fruit pest management guides are now available.

The guides are available for free in PDF form. Hard copies may be purchased.

2025 Spray Bulletin for Commercial Tree Fruit Growers Click here for PDF.

2025 Pest Management Guides
2025 Commercial Horticultural and Forest Crops (including Commercial Small Fruit, Commercial Vineyards, Commercial Hops) Click here for pdf.
2025 Home Grounds and Animals (including HomeFruit). Click here for pdf.
2024 Field Crops Click here for pdf.

More later,
Doug

2024 Fruit Pest Management Recommendations Posterd

Hello, everyone,

This year's revisions to our fruit pest management guides are now available.

The guides are available for free in PDF form. Hard copies may be purchased.

2024 Spray Bulletin for Commercial Tree Fruit Growers Click here for PDF.

2024 Pest Management Guides
2024 Commercial Horticultural and Forest Crops (including Commercial Small Fruit, Commercial Vineyards, Commercial Hops) Click here for pdf.
2024 Home Grounds and Animals (including HomeFruit). Click here for pdf.
2024 Field Crops Click here for pdf.

More later,
Doug

Appearance of Spotted Lanternfly Adults

Hello, everyone,

This week, spotted lanternfly (SLF) adults began their appearance. There was an appearance of an adult in a vineyard in Bedford County on July 19. There is a possible appearance a day or so earlier that is being follow up on.

This map includes the most recent updates in geographic spread of SLF in Virginia, generated in the Insect Identification Lab in the Department of Entomology. Red counties are included in the VDACS quarantine; counties in orange have established populations but are not yet in quarantine.

The adult stage poses the greatest risk of immigration into vineyards, because of its mobility and attraction to grapevines. If adults are just showing up in an area, there is no need to overreact. In areas where SLF has been present in an area for a season or two, the pest pressure is likely to be higher. In the coming weeks, play close attention, looking for adults on cordons and canes. A provisional action threshold in vineyards is 5-10 adults per vine. I emphasize the term provisional. This may go up or down as we gain further experience with this insect in our vineyards. There is often a strong edge effect with this insect, and border sprays may be able to handle the problem, without spraying the whole block.

The Pest Management Guide chapters for Commercial Vineyards, Small Fruits and Hops can be found at this link (https://www.pubs.ext.vt.edu/456/456-017/456-017.html). There are several materials listed for this time of the season, when adults are the target. Once sprays start, reassess frequently. Pay close attention to the maximum applications or amounts applied per season, and watch preharvest intervals. I would very much like to hear more about this as it unfolds at your sites.

Here is a link to my SLF page (https://www.virginiafruit.ento.vt.edu/SLF.html). There is a table linked there listing SLF materials, with PHI and seasonal max levels. There are fact sheets post for SLF for general information, management in vineyards and in residential areas.

Let me know if you would like to discuss SLF at your location.
More later,
Doug

2023 Revisions to Fruit Pest Management Recommendations

Hello, everyone, We now have this year's updated pest management guides posted. The guides are available free online in PDF, and will also be available for purchase. 2023 Pest Management Guides
2023 Commercial Horticultural and Forest Crops (including Commercial Small Fruit, Commercial Vineyards, Commercial Hops)
2023 Home Grounds and Animals (including Home Fruit)
2023 Field Crops

2023 Spray Bulletin for Commercial Tree Fruit Growers.

Watch for more later!
Doug

Update on Spotted Lanternfly

Hello, everyone, It's time for an update on spotted lanternfly (SLF), as it continues its spread through the state. After the discovery of SLF in Winchester in 2018, a quarantine zone was erected - the insect was first found in Winchester and Frederick County, but as it spread, the quarantine zone included, in addition to those areas, Clarke and Warren Counties. In 2022, the zone was significantly expanded to include Albemarle, Augusta, Carroll, Nelson, Page, Prince William, Rockingham, Rockbridge, Shenandoah and Wythe Counties, plus the cities of Buena Vista, Charlottesville, Harrisonburg, Lexington, Lynchburg, Manassas, Manassas Park, Staunton and Waynesboro. The map of the quarantine zone is here:

The disjunct part of the range, in Wythe and Carroll Counties (near the North Carolina border), is almost certainly due to human-assisted transport. The site in Carroll County is near a parking lot at the junction of I-77 and Rt 58. A notable new find late this season was in the New River Valley, in the city of Radford (this does not yet show up in the quarantine zone - there is always a lag in the quarantine map because of administrative issues in expanding a quarantine zone). Dead adults were found at office windows across the street from private land with tree of heaven. The discovery was aided by spiders, whose webs on the window sills ensnared the adults!

At this time of year, SLF is in the egg stage. Eggs are laid not only on tree of heaven, but the bark of other trees, as well as inanimate objects. In vineyards with established populations, egg masses may be seen in high numbers on trellis posts. In one vineyard in northern Virginia, masses were seen in high numbers on treated wood end posts, shown here. Note how the presence of protective covering over the eggs deposited by the female varies from complete to absent.

One troubling observation was the concentration of egg masses in the inner (concave) surfaces of roll-formed steel trellis posts. This protective behavior will likely result in difficulties in achieving spray coverage with the development of effective ovicides. See the video here.



There will be further updates as this pest increases its presence in Virginia. More later, Doug P.

Resources to Help in SLF Quarantine Compliance and Management

Hello, everyone,

Spotted lanternfly (SLF) is a potentially devastating pest of grape, now expanding its spread in Virginia. In July 2022, VDACS expanded a quarantine zone from 3 counties to 12, including contained independent cities.

Many vineyards and wineries will now need to deal with the quarantine protocol. At least one person per company will need to get certified through a short, on-line training session ($6.00). That person may train others in the company to assure compliance. All shipments and vehicles leaving the quarantine zone will need to be inspected. Information on the quarantine protocol may be found here (https://www.vdacs.virginia.gov/plant-industry-services-spotted-lanternfly.shtml). This site contains the protocol as well as the current version of the quarantine map.

The training required for certification is easy and inexpensive. Access to the training may be found here (https://register.ext.vt.edu/search/publicCourseSearchDetails.do;jsessionid=E3FEE1B1C1921BA6848B382063FC0BDE?method=load&courseId=1066947).

When doing inspections for quarantine compliance, it will be necessary to know what life stages of SLF can be expected. We have graph posted online that conveys this information clearly (https://www.pubs.ext.vt.edu/ENTO/Ento-268/ENTO-268.html). This can be posted where appropriate in your operation.

Theresa Dellinger and Eric Day in the Department of Entomology have created a useful aid for the public on the SLF quarantine, entitled "What Virginians Need to Know About SLF Quarantine expansion" (https://www.pubs.ext.vt.edu/ENTO/ENTO-319/ENTO-319.html).

Beyond matters of quarantine compliance, we have online resources for SLF management. There is a fact sheet on SLF management, available in English and Spanish, available here (https://www.pubs.ext.vt.edu/ENTO/ENTO-323/ENTO-323.html). In a similar fashion, a fact sheet for SLF management in residential areas (https://www.pubs.ext.vt.edu/ENTO/ENTO-322/ENTO-322.html).

Needless to say, SLF is covered in our annual chemical control recommendations for vineyards and home fruit. The risk to tree fruits is not considered to be as great; SLF will be included here as needed. It should be noted that orchardists will still need to deal with quarantine issues.

VCE Pest Management Guide for Commercial Vineyards (https://www.pubs.ext.vt.edu/content/pubs_ext_vt_edu/en/456/456-017/456-017.html)

VCE Pest Management Guide for Home Fruit (https://www.pubs.ext.vt.edu/456/456-018/456-018.htmls.html)

Last but not least, I maintain a spotted lanternfly page in the Virginia Fruit Site ( https://www.virginiafruit.ento.vt.edu/SLF.html). I intend for this to be one-stop shopping for matters on SLF, and all the above links are active there.

I hope this is useful. More later, Doug

Spotted lanternfly update: Large expansion of quarantine zone

Hello, everyone,

In May 2019, the Virginia Department of Agriculture and Consumer Services (VDACS) announced the establishment of a quarantine zone for spotted lanternfly (SLF). I posted on this here on 28 May of that year, and again on 3 June, when a public open house was announced to discuss compliance with the program. The quarantine zone initially contained Frederick, Clarke and Warren Counties plus the City of Winchester. A significant expansion of the zone is now planned, and will be formally announced in the next week or so. The quarantine zone additions will include the counties of Albemarle, Augusta, Carroll, Page, Prince William, Rockingham, Rockbridge, Shenandoah and Wythe, plus the cities of Buena Vista, Charlottesville, Harrisonburg, Lexington, Lynchburg, Manassas, Manassas Park, Staunton and Waynesboro. Here is the new zone map:

Here is a link to more information on the quarantine (https://www.vdacs.virginia.gov/pdf/spotted-lanternfly-quarantine.pdf). There will be public informational sessions to discuss the program, and facilitate compliance. One such meeting will be held on Aug 1, 5:50-8:30 PM, at King Family Vineyards. For more information, contact Grace Monger, gimonger@vt.edu (free with pre-registration, $10 at the gate). I will announce other sessions as I learn of dates.

One of the conditions of the quarantine is that at least one person within each company (vineyard, winery, orchard, hops yard, etc.) be certified to inspect and approve vehicles or shipments leaving the quarantine zone. The current certification program is linked here. Cost for a certification is $6.00.

The quarantine zone is being expanded because SLF continues to spread in Virginia. Different maps are prepared reflecting this spread. There are understandable differences in details among maps depending on the nature of programs - approvals that are needed for a quarantine, official identification of SLF samples, etc. Here are two current maps. The first has been developed within the Department of Entomology at Virginia Tech, by Eric Day and Theresa Dellinger. The second is maintained in a SLF site by the New York State IPM program at Cornell University.

These two maps reflect two infested counties not yet included in the quarantine: Campbell and Loudoun. An important point of the Cornell map is that it includes the whole range of SLF. A significant point here is that SLF has turned up in North Carolina, the first infestation for this state, in Forsythe County, Close to I-44. More information on the NC infestation can be seen here.

Summary: Important take-away points here are that SLF has continued its spread, now including the whole Shenandoah Valley, further incursions in the Piedmont of Virginia, and a significant jump into southern Virginia, almost certainly assisted by human transportation, at the junction of two major highways. There has been an expansion into North Carolina, close to (though not adjacent) to Carroll and Wythe Counties. VDACS is set to announce a significant expansion of the SLF quarantine zone in Virginia. Watch for annoucements of informational meetings in affected counties.

You can contact me for information on spotted lanternfly biology or management. For questions on the quarantine program itself, contact VDACS at spottedlanternfly@vdacs.virginia.gov, or 804-786-3515.

More later, Doug

Update on spotted lanternfly - first adults

Hello, everyone,

We are at crucial stage of development for our population of spotted lanternfly, both in terms of range expansion and seasonal phenology. You may remember that at the end of last season, we had detected SLF at a commercial vineyard for the first time, in a vineyard north of Winchester (we had earlier detected it on a table grape planting in Winchester). This week we found fourth instar nymphs at two commercial vineyards southwest of Winchester. Dr. Johanna Elsensohn, a post doctoral researcher with USDA-ARS, found a single nymph on a vine. At both of these Frederick County vineyards we found nymphs on tree of heaven on both sides of the blocks – the vineyards are essentially surrounded!

Fig. 1-2. Spotted lanternfly fourth instar nymphs on tree of heaven surrounding a vineyard.

Yesterday, the first adults of SLF for this season were reported. This is an important time of the season, since the adult stage is the main dispersal stage. From now until fall, there will be a time of movement into vineyard blocks if SLF is established in the area. Growers in such areas should be watchful. Adults will form large feeding aggregations, and can impost a large drain on the vine.

Fig. 3-4. Spotted lanternfly fourth instar nymphs on tree of heaven surrounding a vineyard.

In both of these vineyards, there were stands of young tree of heaven that had grown from cut trees. It will be helpful to remove tree of heaven, but it is important to not simply cut the trees with out supplemental herbicide treatment, because of the way these trees regenerate. Figs. 2 and 3 show nymphs on such small trees (Figs. 1 and 4 contain nymphs on mature trees). We are fortunate in having only a single generation of SLF. If we start the season with a low population of young nymphs, it is unlikely that significant immigration will occur, and additional sprays may not be needed. This can change with the mobility of winged adults.

Fig. 5. Adult spotted lanternfly

This year is likely to be a year of additional commercial vineyards with populations of SLF. Apple and peach orchards may also see feeding aggregations, but these may be transient. Hops are also fed upon, but more information is needed on duration and severity, Please let me know of observations at your plantings.

More later,
Doug

Cicada aftermath, and bird/cicada controversy

Hello, everyone,
This year's emergence: This emergence of Brood X periodical cicada has now pretty much run its course – the adult stage anyway. If you have young fruit trees, it might be helpful to prune off damaged branches – this would prevent the nymphs from establishing on roots, helpful in the first formative years of the tree. Eggs normally hatch 6-10 weeks after oviposition. For us in Virginia, this was mainly a northern Virginia issue. Brood X extends up through eastern Pennsylvania and New Jersey (remember this when you get to the hot topic note toward the end!) There were also populations of Brood X south of Virginia (parts of North Carolina, Tennessee and Georgia). Here are the maps for Broods IX and X:

Fig. 1. Maps of periodical cicada Broods IX and X, from Marlatt (1907)

The broods were characterized and named by the USDA entomologist Charles Marlatt in 1907 (Marlatt 1907). But while Marlatt made a great formal study of these insects and determined the geographical broods, he was not the first to determine the 17-year cycle. A free African-American naturalist, Benjamin Banneker, living in Maryland, born in 1731, reported this after an 1800 emergence (Barber and Nkwanta 2014). He successfully predicted subsequent emergences. Both of these individuals played other important roles – Banneker helped survey the borders of Washington DC, and Marlatt led the creation of the first regulations designed to protect us from invasive pests).

There are three Magicicada species that make up each brood of periodical cicada. The local species composition can very a lot, even within a county. Last week we sampled cicadas in Frederick County: at Fort Collier in Winchester, 94% were composed of M. cassini (34:2), while at Star Tannery in the southwestern part of the county, 76% were M. septendecim (16:5). M. cassini are smaller, with the underside of the abdomen completely black, compared with the larger M. septendecim, with red on each sclerite.

Fig. 2. Side-by-side comparison of Magicicada septendecim (top) and M. cassini (bottom).

While M. cassini may lay their eggs in smaller branches, I’ve seen no comparison of the economic impact of the species, and they are treated equivalently.

It was originally thought that most egg-laying occurred distal to the clusters of grapevines, and so on grape, injury was most important on young vines. Clearly some of the injury we saw was basal to clusters, and those clusters will be lost. While young vines are at particular risk, there is clear economic impact to bearing vines. At this point, it is not recommended to prune out affected shoots, but rather wait until winter pruning.

Fig. 3. Egg nests of periodical cicada may occur either above or below grape clusters.

Coming attractions: The adults of this emergence of Brood X are now a recent memory. As I’ve pointed out in extension presentations, it is wise to avoid planting a new orchard or vineyard a year or two before an anticipated emergence. However, we don’t usually give this warning long enough in advance for sufficient planning, given the lead time needed by nurseries, to get desired scion/rootstock combinations. Here is a listing in order of appearance of broods relevant to Virginia. The most important ones will likely be XIX, II, IX and X. Click on the Brood numbers to see a map.

Brood XIX (13 year): (Southside Virginia) The Great Southern Brood (2024)
Brood XIV: southern OH, KE, TN, MA, MD, NC, PA, northern GA, southwestern VA and WV, parts of NY and NJ (2025)
Brood I: The Blue Ridge Brood: Western VA, WV (2029)
Brood II: East Coast Brood: CT, MD, NC, NJ, NY, PA, DA, VA, DC. (2030)
Brood V: eastern OH, western MD, southwestern PA, northwestern VA, WV, NY (Suffolk Co.) (2033)
Brood IX: southwestern VA, southern WV, western NC (2037)
Brood X: The Great Eastern Brood: NY, NJ, PA, DE, MD, DC, VA, WV, NC, GA, TN, KE, OH, IN, IL, MI (2038)

Addressing a hot topic: Another issue has been broached in the news in the past few days that I would like to comment on. There has been a recent wave of unexplained bird deaths and illness in northern Virginia. Symptoms include blindness or crusty eyes, and neurological problems. The idea was postulated that eating cicadas was responsible for this bird morbidity/mortality. This is circumstantial at best. There were no such problems noted last year in Brood IX in southwest Virginia, nor in earlier emergences of Brood X in northern Virginia.

https://www.ecowatch.com/mystery-disease-killing-birds-2653532689.html

https://www.npr.org/2021/06/28/1011043752/correlation-not-causation-brood-x-cicadas-and-regional-bird-deaths?utm_source%C3%BAcebook&utm_medium%C3%BEws_tab&utm_content%C3%BFgorithm

Cicadas have long been considered a nontoxic food for birds (Leonard 1964, Steward et al. 1988, Williams and Simon 1995). Birds feeding on cicadas have included European starling, common grackles, American robin, wood thrush, blue jay, yellow-billed and black-billed cuckoos, red-winged blackbirds, house sparrow, redheaded woodpecker, tufted titmouse, vireos, terns, laughing gull and ducks. I birded last year with friends in areas of Brood IX adult periodical cicada activity, and we saw no unusual bird behavior (the worst thing was not being able to hear birds above the cicada singing!). Periodical cicadas present an important part of nutrient cycling in forests, and are a nutritional resources for predators (Wheeler et al. 1992).

There is an entomopathogenic fungus, Massospora, that may provide some natural mortality to periodical cicadas. There are compounds in Massospora that are psychoactive in cicadas, causing them to change their behavior (Boyce et al. 2019). One compound in Massospora, cathinone (Boyce et al. 2019), has been known to have psychoactive properties in humans (Langman and Jannetto 2020). But there is no record of eating Massospora-infected cicadas being harmful to birds. Moreover, Massospora is a natural component of the system, and unusual bird maladies are not reported following cicada emergences.

One interview (linked above) speculated whether birds might be picking up insecticides or heavy metals from sprayed cicadas. In an earlier study (Clark 1992), cicadas were not found to be a source of significant levels of organochlorine insecticides or heavy metals for birds. Organochlorines have been replaced by other classes of chemistry, but that group was longer lived, and would bioaccumulate. Modern insecticides should pose less of a hazard in this regard.

So in summary, here are my thoughts on cicada involvement with the bird death/sickness syndrome. If the situation changes, or new information becomes available I’ll let you know:

• There was no issue with bird mortality/morbidity with last year's brood IX, nor northern Virginia Brood X last time.
• Massospora has been a part of the landscape for a long time, with no apparent link to birds.
• There was no apparent bird problem in PA or NJ, nor Tennessee or North Carolina, where Brood X was abundant. Note: Some increasing bird mortality was seen in southern NJ after cicadas had disappeared, well after the outbreak in northern Virginia. This weakens the case for synchrony between cicadas and bird deaths.
• There have been changes in pesticides used over the years, but from last year in Brood IX, there wouldn't be any difference with this year in Brood X.
• If cicadas, fungus, or pesticides are involved, there must be some other environmental change to shift their importance.

Reporting Bird Mortality: The Department of Wildlife Resources has created a reporting form for cases of sick or dead birds:

https://dwr.virginia.gov/wildlife/diseases/bird-mortality-reporting-form/

More later,
Doug

References

Barber, J. E., and A. Nkwanta. 2014. Benjamin Banneker's original handwritten document: Observations and study of the cicada. Journal of Humanistic Mathematics 4: 112-122.
Boyce, G. R., E. Gluck-Thaler, J. C. Slot, J. E. Stajich, W. J. Davis, T. Y. James, J. R. Cooley, D. G. Panaccione, J. Eilenberg, H. H. De Fine Licht, A. M. Macias, M. C. Berger, K. L. Wickert, C. M. Stauder, E. J. Spahr, M. D. Maust, A. M. Metheny, C. Simon, G. Kritsky, K. T. Hodge, R. A. Humberi, GullionT., D. P. G. Short, T. Kijimoto, D. Mozgai, N. Arguedas, and M. T. Kassona. 2019. Psychoactive plant- and mushroom-associated alkaloids from two behavior modifying cicada pathogens. Fungal Ecol. 41: 147-164.
Clark, D. R. 1992. Organochlorines and heavy metals in 17-year cicadas pose no apparent dietary threat to birds. Environ. Monit. Assess. 20: 47–54.
Langman, L. J., and P. J. Jannetto. 2020. Toxicology and the clinical laboratory pp. 917-951. In W. Clarke and M. A. Marzinke (eds.), Contemporary Practice in Clinical Chemistry. 4th Ed. Elsevier.
Leonard, D. E. 1964. Biology and ecology of Magicicada septendecim (L.) (hemiptera: Cicadidae). J. New York Entomol. Soc. 72: 19-23.
Marlatt, C. L. 1907. The periodical cicada. U. S. Dept. Agric. Bur. Entomol. Bull. 71: 1-181. Steward, V. B., K. G. Smith, and F. M. Stephen. 1988. Red-winged blackbird predation on periodical cicadas (Cicadidae Magicicada spp.) - Bird behavior and cicada responses. Oecologia 76: 348-352.
Wheeler, G. L., K. S. Williams, and K. G. Smith. 1992. Role of periodical cicadas (Homoptera: Cicadidae: Magicicada) in forest nutrient cycles. Forest Ecol. Manag. 51: 339-346.
Williams, K. S., and C. Simon. 1995. The ecology, behavior, and evolution of periodical cicadas. Annu. Rev. Entomol. 40: 269-295.

Brood X of Periodical Cicada Active

Hello, everyone,

Periodical cicada does its most important injury by its oviposition behavior, using its ovipositor to make slits in shoots were eggs are deposited. The section of shoot or branch beyond this point dies, resulting in a brown flagging. Usually, this occurs beyond where fruit are growing, but this can vary and growers should be observant. The injury has its greatest impact on young fruit trees and grapevines, and these plants should be protected during periods of adult activity.

This year's appearance periodical cicada's Brood X has commenced. First appearance of emergence from the soil was seen on April 28 (thank you Adria Bordas for the notice!). Development was slowed by the period of cool weather we experienced. With warmer activity, adults are now becoming more active, and Mark Sutphin has noted this activity in Frederick County orchards. For more details on periodical cicada, follow this link for a 20-minute recorded presentation: https://www.virginiafruit.ento.vt.edu/PeriodicalCicada2020 There are 15 broods of periodical cicada (12 17-year forms, three 13-years forms in more southern areas). The details of distribution may change with changes in land use. Brood X (this year's brood) will be most intense in northern Virginia, north through eastern Pennsylvania and New Jersey. However, there are pockets in southwestern Virginia and North Carolina. If any of you note activity in southwestern counties, and in any counties around the edge of the range (see map), please le me know, so that we can update our records!

More later, Doug

Spotted Lanternfly Update

Hello, everyone,

Spotted lanternfly is the newest invasive our fruit growers are having to deal with - fortunately, it is still limited in geographic range, but this range continues to expand. First egg hatch this season was reported on April 28. Development was slowed by the period of cool weather we experienced, but more nymphs are now being seen. SLF continues to expand its most intensive infestation in Frederick County, with several counties added. Clarke and Warren Counties now have scattered breeding populations, and individual finds have been made in Shenandoah,Page, Madison, Fauquier, Prince William, and Augusta Counties. The rankings for some of these sites may increase as further data are collected. It is important to note that there may not be breeding populations in some of the latter counties because of the ability of individual SLF to hitchhike. The VDACS-designated quarantine zone has been expanded beyond Frederick County to include Clarke and Warren Counties. Grape is the most vulnerable commercial crop. In October we discovered SLF at a commercial vineyard for the first time. However, the SLF range now surrounds some vineyards, so further detections in some of our northern vineyards are likely this season. SLF has also been detected at commercial orchards in Frederick County; impacts will be followed there as well. Please let me know of detections you may make in your vineyards. In addition, you can report finds of SLF into the following portal: https://ask2.extension.org/widget.html?team_id=1981?default_location=VA?default_county=All In order to move regulated articles from the infestations zone, certification is needed. This certification is available at this location: https://register.ext.vt.edu/search/publicCourseSearchDetails.do;jsessionid=E3FEE1B1C1921BA6848B382063FC0BDE?method=load&courseId=1066947 More later, Doug

2021 State Berry School Rescheduled

Hello, everyone, Because of the inclement weather today, the state berry school I posted a few days ago, has been rescheduled. The new dates for the Virginia Berry School are Thursday, March 4th through Friday, March 5th. If you are registered already, you do not need to change anything, the link sent by VSU is still valid to log in. If you cannot attend on those days, the sessions will be available online after the event is over for viewing. If you know of anyone who still wants to register, we have reopened registration (https://www.ext.vsu.edu/events/2021/02/18/berry-school). If you need a refund because you no longer wish to attend, please contact Jessica Harris (jharris@vsu.edu) and you will receive a full refund. We hope to see you there! Doug P.

Southeastern Strawberry School Webinar Series

Hello, everyone, The Southern Region Small Fruit Consortium, in which Virginia Tech is a member, has organized the Southeastern Strawberry School Webinar Series. These webinars will take place throughout 2021. This series is hosted by the University of Arkansas in collaboration with university specialists from across the southeastern region. This webinar series is sponsored by the Southern Region Small Fruit Consortium and is open *free* to county agents, and growers. Follow this link for more details, and information on how to sign up. Doug P.

2021 State Berry School

Hello, everyone, A two-day, on-line berry school is scheduled for Feb 18-19, organized by our extension partners at Virginia State University. Follow this link to register for the 2021 Virginia Berry School, https://www.ext.vsu.edu/events/2021/02/18/berry-school. This two day event will provide information about the production potential, and health benefits of berry crops, including blueberry and blackberry. Please share this information with interested individuals. See you online! Doug Pfeiffer

Small Fruit News - availability and reader survey

 

Hello, everyone,

The Southern Region Small Fruit Consortium is a group of stakeholders interested in small fruit production, representing growers, agents and university faculty in Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, Arkansas, and Tennessee.  The Consortium publishes a quarterly newsletter, the Small Fruit News (https://smallfruits.org/category/small-fruit-news/).  Last year, the SFN newsletter was revamped, and a new editorial board established.  For the first three issues for 2020, articles were posted as web articles alone.  The Fall issue (https://smallfruits.org/category/small-fruit-news/fall-2020/) also contains a link to a PDF version.

We have posted a survey for readers to weigh in on utility of Small Fruit News, and in particular your desire to include a PDF option.  Could you please take a few minutes and respond to the survey?  The link is included below.

Small Fruit News Feedback Survey: https://docs.google.com/forms/d/e/1FAIpQLSf8Uvd9QDTJz59lkw4VUBUWoR0fQBRNJye3SwYF7zF0Ro-AbA/viewform

You can get find out more about the Small Fruit Consortium at: https://smallfruits.org/

Thanks for your help in keeping the Small Fruit News useful!

Doug P.

Management of Spotted-Wing Drosophila in Berry Crops

Since its introduction and spread in the US from 2008-2012, spotted-wing drosophila (SWD), Drosophila suzukii (Matsumura), SWD has presented a huge problem for berry growers.  SWD is a difficult pest to control.  Because of its high fecundity and number of generations, there is a high risk of insecticide resistance.  Consequently, growers should use a combination of tactics.  Because of the need to rely on non-chemical approaches as much as possible, there will be overlap in approaches between conventional and organic growers as they work to manage this common problem.  Nevertheless, because of specific concerns and constraints between the two groups of growers, specific comments will be made.

Fig.1. Spotted-wing drosophila adults. a. male showing black spots near wing-tip. b. serrated ovipositor of female.

Hosts: Hosts include caneberries, blueberries, strawberries, grapes and cherries.  Caneberries and blueberries are at greatest risk.  Grape is not an ideal host, with lower attack and survival rates than other berry crops.  Nevertheless, attacks by SWD can give rise to larval infestation and resulting sour rot.  There are differing levels of susceptibility among different winegrape cultivars, depending on variety (Shrader et al. 2019), ranging from Viognier (more susceptible) to Petit Manseng (less susceptible).

Description:  By now, most berry growers are familiar with this insect and its appearance.  The adult fly looks similar to native vinegar flies, with the main exceptions of a black spot on the leading edge of the wing in the male (Fig. 1a), and the large ovipositor of the female (Fig. 1b).  This large, serrated ovipositor allows the insect to insert eggs into the flesh of a ripening fruit, allowing larval establishment ahead of other drosophilids, which colonize rotting or overripe fruit material. Eggs are white, elongate oval, inserted under the skin of the berry, with long respiratory filaments from one end (Fig. 2a).  These respiratory horns may be found protruding from an oviposition site with magnification (Fig. 2b). 

Fig. 2. Spotted-wing drosophila eggs. a. exposed egg with respiratory filaments. b. Respiratory filaments protruding from oviposition hole in a blueberry.

Larvae are translucent maggots 2-3 mm long, with black mouth hooks visible at the anterior end (Fig. 3).  Silvery white tracheal tubes may be visible through the dorsal cuticle with magnification.  Respiratory projections are present on the posterior end, giving an appearance of being pointed at each end.  Pupae are brown, elliptical, about 3 mm long, with respiratory projections from the hind end.

Larvae are translucent maggots 2-3 mm long, with black mouth hooks visible at the anterior end (Fig. 3a).  Silvery white tracheal tubes may be visible through the dorsal cuticle with magnification.  Respiratory projections are present on the posterior end, giving an appearance of being pointed at each end.  Puparia (covering of the actual pupa) (Fig. 3b) are brown, elliptical, about 3 mm long, with respiratory projections from the hind end.

Fig. 3. Spotted-wing drosophila larvae in a raspberry (a), and puparium (b)

Biology: In eastern Asia, there are up to 13 generations.  A life cycle can be completed in 8-14 days, but adults can live up to 9 weeks.  Females use the atypically large ovipositor to lay eggs in fruits as they are ripening, earlier than other drosophila species.  Eggs are inserted under the skin of ripening fruit; each female lays 7-16 eggs/day. Eggs hatch in 1-3 days, and larval feeding on the flesh causes a collapse of localized tissue after another 2 days, followed by growth of fungal or bacterial organisms.  Updates will be posted in the spotted-wing drosophila page within the Virginia Fruit web site:  https://www.virginiafruit.ento.vt.edu/SWD.html

Monitoring:  In general, traps are not powerful enough to serve as a control.  Traps should be used to detect activity, and when flies are detected, make sure that other control measures are in place.  Several commercial traps are available (Trece and Scentry).  A trapping guide has been posted (Wallingford et al. 2018), with discussion of several baits, and comparing commercial with homemade traps.  Traps using homemade baits of either yeast or apple cider vinegar may be used for monitoring.  Traps using apple cider vinegar (ACV) alone are attractive to flies and less odorous to work with than with yeast added; traps with added yeast may be somewhat more sensitive, but fluid should be replaced with each service of the traps.  A combination of ACV and red wine (60:40) is more attractive than ACV alone (Shrader 2017).  If available, brown rice vinegar is more attractive than ACV (Willbrand and Pfeiffer 2019).  Traps should be checked at least weekly.  Most of the Drosophila flies collected will not be SWD, so the flies collected must be checked carefully.

Control: 

  Chemical control:  Control measures are directed against the adults; there are no effective controls for larvae in the fruit.  As vulnerable fruit approach ripeness, weekly spray applications should be made.  Because of the high number of offspring and number of generations, there is a high risk of development of insecticide resistance.  Consequently, insecticides with different mode of actions should be rotated to prolong the effective life of insecticides.  Organophosphates (malathion and phosmet) are effective (check labels for registrations on specific crops), as are pyrethroids (be wary of induction of secondary pests).   Spinosyns offer an additional mode of action class, with spinetoram having greater efficacy than spinosad.  See Table 1 for a list of insecticides available for SWD on the most vulnerable crops.  Included are the maximum number of applications (or amounts of material) allowed per season and the IRAC class of mode of action.   This is important in designing rotations - it will be helpful to reserve materials effective against SWD until properly timed for that pest.  Organically approved treatments are included in the table.  It should be noted that the organic materials generally have a shorter residual life, and lower efficacy that synthetic insecticides.  It is also worth remembering that it may be worth keeping a material in a rotation even if of lower efficacy, to help keep the SWD population from adapting to other products.

Table 1.  Insecticides for Spotted-Wing Drosophila, listed by Crop and Mode of Action

Blueberry         Caneberry               Grape                Strawberry

IRAC 1A – carbamates

Lannate 90SP

              Rate                         0.5-1 lb                         --                                   --                                --

              PHI                         3d                                  --                                   --                                --

              Applics/Season       4                                    --                                   --                                --

IRAC 1B - organophosphates

Malathion 8F (malathion)

Rate                        2.5 pt ³                          2 pt                             1.88 pt                        1.5‐2 pt

PHI                         1d                                 1d                                3d                               3d

Applics/Season       2                                   4                                  2                                 4

Imidan 70WSB (phosmet)

Rate                        1.3 lb                            ‐‐                                  1.3‐2.12 lb                  ‐‐

PHI                        3d                                  ‐‐                                  7‐14d (label)               ‐‐

Applics/Season      5                                    ‐‐                                  6.5 lb                          ‐‐

IRAC 3A – pyrethroids and pyrethrin

Brigade 10WSB (bifenthrin)

Rate                       16 oz                            16 oz                              8‐16 oz                     16 oz

PHI                        1d                                 3d                                   30d                            0d

Applics/Season      80 oz                            2 (32 oz)                        16 oz                          80 oz

Danitol 2.4EC (fenpropathrin)

Rate                    10.6‐16 fl oz                    ‐‐                                   10.6‐21.3 fl oz          10.6 fl oz

PHI                     3d                                     ‐‐                                   21d                            2d

Applics/Season    2                                      ‐‐                                   2                               2 (2.6 pts)

Mustang Maxx 0.8E (zeta‐cypermethrin)

Rate                    4 fl oz                              4 fl oz                             2‐4 fl oz                    ‐‐

PHI                     1d                                     1d                                  1d                              ‐‐

Applics/Season    24 oz                               24 oz                             24 oz                         ‐‐

Tombstone 2EC (cyfluthrin)

Rate                      ‐‐                                      ‐‐                                  2.4‐3.2 fl oz               ‐‐

PHI                       ‐‐                                      ‐‐                                  3d                               ‐‐

Applics/Season²     ‐‐                                      ‐‐                                  12.8 fl oz                    ‐‐

                 (3.2 fl oz/14d)

⁴PyGanic 5EC (pyrethrin)

Rate                     4.5‐18 fl oz                         4.5‐18 fl oz                4.5‐18 fl oz               4.5‐18 fl oz

PHI                      0d                                        0d                               0d                              0d

Applics/Season    n/a                                      n/a                              n/a                             n/a

IRAC 5 – spinosyns

Delegate 25WG (spinetoram)

              Rate                     3-6 oz                                 3-6 oz                          3-5 oz                        --

              PHI                      3d                                       1d                                7d                              --

              Applics/Season    19.5 oz                               6                                  19.5 oz                      --

Radiant 11.7SC (spinetoram)

Rate                     ‐‐                                        ‐‐                                  ‐‐                              6‐10 fl oz

PHI                      ‐‐                                        ‐‐                                  ‐‐                              1d

Applics/Season    ‐‐                                        ‐‐                                  ‐‐                               5

⁴Entrust 80W (spinosad)

Rate                    1.25‐2 oz                           1.25‐2 oz                       1.25‐2.5 oz                1.25‐2 oz

PHI                     3d                                      1d                                  7d                              1d

Applics/Season    3¹                                                          6                                    5                                5

IRAC 28 – diamides

Exirel 10.2EC (cyantraniliprole)

              Rate                    13.5-20.5 fl oz                    --                                    --                              13.5-20.5 fl oz

              PHI                     3d                                        --                                    --                              1d

              Applics/Season   0.4 lb ai                               --                                   --                               0.4 lb ai

Other

IRAC 6/28

Minecto Pro (abamectin/chlorantraniliprole)

              Rate                     --                                         --                                     --                            10 fl oz

              PHI                       --                                        --                                     --                            3d

              Applics/Season     --                                        --                                     --                            40 fl oz

IRAC Unknown

⁴Surround 95WP (kaolin)

              Rate                     25-50 lb                               25-50 lb                         25-50 lb                  --

              PHI                      see label                               see label                        see label                 --

              Applics/Season     --                                         --                                    --                            --

⁴Grandevo (Chromobacterium subtsugae strain PRAA4-1)

              Rate                    2-3 lb                                   2-3 lb                             2-3 lb                       2-3 lb

              PHI                     0d                                        0d                                   0d                            0d

              Applic/Season     n/a                                      n/a                                   n/a                           n/a

¹ 3 applications per crop, 6 applications per calendar year.

² See label. Maximum seasonal rate depends on use of other products.

³ This rate may be available as a 24C registration; check for state labels. Full Sect 3 label rate is 1.25 lb.

⁴ OMRI-approved, suitable for organic production.

Our Southern Region Small Fruit Consortium provides recommendations for SWD in the pest management guides for caneberries, blueberries, strawberries and bunch grapes.  In addition, SWD is addressed in our Virginia VCE Small Fruit recommendations (https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/456/456-017/ENTO-337B.pdf).

Caneberries: https://smallfruits.org/files/2020/01/2020-Caneberry-Spray-Guide.pdf

Blueberries: https://smallfruits.org/files/2020/02/2020-Blueberry-Spray-Guide.pdf

Strawberries: https://smallfruits.org/files/2020/02/2020-Strawberry-IPM-Guide.pdf

Bunch grapes:  https://smallfruits.org/files/2020/02/2020-Bunch-Grape-Spray-Guide.pdf

If SWD needs to be controlled in a vineyard setting, it will helpful to make an application just before berries close in clusters, since many oviposition strikes are in the protected inner surfaces of the cluster.  Surround has been shown to reduce injury by half, even though this time is well before normal SWD timing.

The flowable formulation of malathion is safer than the EC formulation, but the flowable formulation may be in shorter supply.  When using the EC (oil-based) formulations, use caution if also applying the fungicide captan.  The oil can act as a penetrant, potentially causing phytotoxicity).

Cultural control:  Netting of 80g weight was effective in controlling injury (McDermott and Nickerson 2014, Riggs et al. 2016, Ebbenga et al. 2019).  Lighter grades (larger mesh) are not effective.  While netting is initially expensive, it becomes cost effective because it may be used for several years.

Harvest fruit promptly and thoroughly to eliminate breeding sites. It is important to harvest all fruit, including those in the interior and lower parts of the plant canopy.  This can be problematic in pick-your-own operations.  This issue should be kept in mind once SWD established in an area, since at times grape growers may leave berries on the vine to allow greater development of some harvest parameters.   Any overripe or rotten fruit nearby should be destroyed.  In vineyards, pomace produced during the crushing process should not be dumped near the producing vineyard block.  This can become a source for many SWD.

When berries are harvested, it will be helpful to get them as cool as possible, as soon as possible.  There is complete mortality of larvae in fruit held for 96 hours at 35˚F, and below 40˚F, eggs and larvae don’t develop (Bolda 2010, Burrack 2016).  In most cases, such uniform holding conditions are not maintained; fruit cooling should be considered a component of SWD management and not a sole control tactic.

Biological control: Because of the ability of SWD to encapsulate and kill the eggs of our native parasitoid wasps, biological control has not been successful.  Research is underway to find parasitic species that are able to attack this species.

Resources:

Bolda, M. 2010. Length and magnitude of fruit cooling and spotted wing drosophila mortality, Strawberries and Caneberries. Univ. Calif. Agric. Nat. Res. https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=2474.

Burrack, H. 2016. Preventing and managing spotted wing drosophila infestation. NC State Extension.  Entomology - Insect Biology and Management.  https://entomology.ces.ncsu.edu/2016/06/preventing-and-managing-spotted-wing-drosophila-infestation/.

Ebbenga, D. N., E. C. Burkness, and W. D. Hutchison. 2019. Evaluation of exclusion netting for spotted-wing drosophila (Diptera: Drosophilidae) management in Minnesota wine grapes. J. Econ. Entomol. 112: 2287–2294.

McDermott, L., and L. Nickerson. 2014. Evaluation of insect exclusion and mass trapping as cultural controls of spotted wing drosophila in organic blueberry production. N. Y. Fruit Quarterly 11: 25-27.

Riggs, D. I., G. Loeb, S. Hesler, and L. McDermott. 2016. Using insect netting on existing bird netting support systems to exclude spotted wing drosophila (SWD) from a small scale commercial highbush blueberry planting. N.Y. Fruit Quarterly 24: 9-14.

Shrader, M. E. 2017. Drosophila suzukii (Matsumura) (Diptera: Drosophilidae): Risk assessment for an invasive vinegar fly in Virginia vineyards.  Ph.D. dissertation. Virginia Tech, Blacksburg. 141 p.

Shrader, M. E., H. J. Burrack, and D. G. Pfeiffer. 2019. Drosophila suzukii (Diptera: Drosophilidae) oviposition and adult emergence in six wine grape varieties grown in Virginia. J. Econ. Entomol. 112: 139–148.

Wallingford, A., B. Sideman, and G. Hamilton. 2018. Monitoring spotted wing drosophila (SWD) with traps. Univ. New Hampshire Extension. https://extension.unh.edu/resource/monitoring-spotted-wing-drosophila-swd-traps.

Willbrand, B. N., and D. G. Pfeiffer. 2019. Brown rice vinegar as an olfactory field attractant for Drosophila suzukii (Matsumura) and Zaprionus indianus Gupta (Diptera: Drosophilidae) in cherimoya in Maui, Hawaii, with implications for attractant specificity between species and estimation of relative abundance. Insects 10: 80 (18 p).