OSU Extension Bi-Weekly Fruit & Vegetable Report – September 28th, 2023

The OSU Extension Fruit & Vegetable Report is written/published collectively by OSU Extension staff across the state. 

View a recording of the OSU Extension Bi-Weekly Fruit & Vegetable Report updates below:

Strip Tillage

Strip tillage is a form of conservation tillage that attempts to combine the benefits of no-till and conventional tillage by working only the area where the crop will be planted. Leaving residue cover over the majority of the field protects the soil against erosion and helps to build organic matter, improve aggregate stability, and boost other indicators of soil health. Working the soil in the strip zone warms the soil faster and prepares a better seedbed to support plant growth. 

Components of a strip till unit – A) lead coulter for slicing through residue, B) row cleaners for parting residue, C) shank for fracturing and lifting soil, D) berm-building coulters to shape tilled soil into strip, & E) rolling basket for creating level seedbed. Photo courtesy of Orthsman/Unverferth Manufacturing. 


Strip-till in sweet corn stubble. Photo by Chris Galbraith, OSU Extension.

While strip till targets the benefits that come with integrating the two systems, there are downsides to consider as well. These mostly involve issues with cover crop and/or residue interference with growing the crop. Vigorous cover crops need to be terminated in a timely fashion and crop development can still be delayed in strip-till if the season begins cold and wet. Pests like slugs and voles can also build-up with the increased residue cover. The cost of the equipment can also be a substantial investment which creates a barrier to entry for many growers.

Many vegetables can be grown in strip tillage systems, including cucurbits, sweet corn, snap beans, potatoes, cole crops, carrots, and more. Recent studies at Michigan State University have found a slight yield increase from strip till in vegetable crops, but many of the issues mentioned can impact this (climate, residue management, pest pressure). It is important to consider the factors that go into making strip till a successful venture in order to make the most of the equipment and the practice.

For additional info on strip till in vegetables, check out this website on strip tillage from the Cornell Small Farms Program. 

Wildlife Control in Fruits & Vegetables

This season has been severe in terms of wildlife damage in specialty crops. Animals like deer, groundhogs, voles, raccoons, and birds have caused major losses on some farms. Dr. Marne Titchnell, wildlife program director for OSU Extension, recently gave an in-depth presentation at Farm Science Review on different wildlife mitigation strategies for growers. The information and slides can be found on her blog through the link below:

Managing and Preventing Damage from Wildlife in Fruits & Vegetables

OSU Extension Center for Cooperatives

Opportunities abound for farms when it comes to teaming up to save money and improve effectiveness through joint purchasing, collaborative marketing, and other similar practices. These types of partnerships between farm businesses is captured by the cooperative or “co-op” model where growers access resources and savings by acting together and making decisions as a group in certain scenarios. The Center for Cooperatives at OSU specializes in these sorts of opportunities and can offer guidance to growers who are interested in leveraging the benefits of organizing for collaborative business purposes.

Find more information at the center’s website. Read more about the topic of collaborative marketing in this recent article on the Center of Cooperatives blog.

Crop updates


Cole Crops

Heavy cross striped cabbageworm and imported cabbageworm feeding is still being observed in some brassica plantings. Aphids have made a late season push in brussel sprouts, cabbage, cauliflower and broccoli plantings. Cabbage aphids are typically a grayish color, and are often found amongst a waxy, white secretion which covers their body. Reproduction rates of these aphids are highest in temperatures between 50-68F. Scout for these pests on the underside of younger leaves, between leaf layers and on flower buds or seed stalks. It is recommended to treat cabbage when you see 1-2% of plants infested with aphids. There are a number of products that can be used to treat aphids in cabbage including Movento, Sivanto, Assail, Exirel and Beleaf. Prioritize products that have reduced toxicity (e.g., Beleaf) which will conserve natural enemy communities. Refer to the Midwest Vegetable production guide for other options. 

Cabbage aphid infestation. Photo by Frank Becker, OSU Extension. 


Cucurbits are seeing upticks in a variety of beetles in flowers and fruit. These include corn rootworm species. Spotted cucumber beetles are active. Aphids are also beginning to be found with some more frequency in the fall vine crops. Squash bugs are also active within the crop. Most cucurbits do not have blooms in fields, so pyrethroid and carbamate applications may be applied (e.g., Sevin, Pounce, Capture). Refer to the Midwest Vegetable production guide for other options.

The pumpkin crop has been strong in Ohio this season. Many growers in northwest Ohio were able to manage downy mildew with fungicides. Plectosporium blight has been causing some problems for growers where fungicide spray coverage may not have been as thorough as desired. Most fungicide spray programs being used are adequate to limit impacts from plectosporium blight. Spray penetration into the canopy and coverage across the field is as important as selecting the right product.

Plectosporium blight on pumpkin, identified by light colored lesions on fruit, handles, and vines.  Photos by Frank Becker, OSU Extension.

Fruiting Vegetables 

Late blight has been confirmed in several tomato fields in and around Wayne County. Bacterial diseases have also begun to start, and with cool mornings and heavy dews, it will become increasingly more difficult to manage. 

Several high tunnel producers have reported dealing with broad mites/cyclamen mites in their high tunnel peppers. The mites feed on the fruit while it is still developing and their feeding damage causes the peppers to become russested and misshapen. The leaves may also appear distorted, almost as if they were drifted with herbicides. Keep in mind that these mites are in a different group than two-spotted spider mites. Therefore, it’s important to select control options that are appropriate and effective on this species. Sanitation and crop rotation are also important cultural control measures that need to be taken when dealing with mites in high tunnels.  


Although the growing season is behind us for onions, curing is still ongoing, and some growers have reported some challenges with curing. Make sure that you are providing the proper conditions for curing onions. Less than ideal conditions will result in frustrations and losses of product. Ideal conditions are warm, dry, well ventilated areas. Ideal temperature range is between 75-90F. The other factor that contributes to losses while curing is not curing the best graded onions. Curing is not an attempt to bring quality back, only preserve it. Grading hard for only the best onions to be cured will help reduce the chance that rots begin to develop. Take note of any disease or insect issues that you have observed this year and use these notes to help you next year. Onions that may have had heavy thrips loads, or untreated disease infection during the season are not going to hold up as well as desired during the curing process. 

Green onions are seeing thrips populations slow down. Typically, thrips populations will decrease as we enter into Autumn and see these species move onto weedy hosts. 


Sanitation is an important component of an integrated disease management program. In small fruit and tree fruit alike, there are diseases that can over winter on infested fruit, foliage and branches. As the season winds down, it is still important to scout for diseases that may be present, identify the disease and have a plan of action to manage the disease. Finding and removing mummy fruit, which are dried and shriveled fruit that are typically full of fungal structures, will help to significantly reduce disease inoculum from the production area. Too, mowing and mulching or raking away the leaves from around the trees and bushes reduces the amount of viable inoculum that may be overwintering in foliage. Much progress can be made towards disease management with efforts made in the fall. Taking these steps, and committing to them long term, helps to break disease cycles and reduce the overall pathogen load over time. 

Fruit rots are being observed in apples, including white rot and bitter rot. Bitter rot is common in apples during warm, wet conditions. For more information, take a look at this OSU article on bitter rot in apple. Marsoninna blotch is also found on apples. 

The pawpaw crop in Ohio this season has been later and smaller than past years. Pawpaw is a niche crop that is gaining popularity with Ohio consumers and can be used as an ingredient in specialty craft beers, ice cream, and other value-added items. For more information on pawpaw production, check out this factsheet from Cornell University. Learn more about the pawpaw industry in Ohio by visiting the Ohio PawPaw Growers Association website.

Pawpaw fruit cluster. Photo by Clemson University. 


Upcoming Events

September 30, Albany, OH OEFFA CSA Veggie Farm Tour

December 5 – 7, Grand Rapids, MI, Great Lakes Fruit, Vegetable, & Farm Market Expo 

January 15 – 16, Columbus, OH, 2024 Ohio Produce Network

February 15 – 17, Newark, OH, 2024 Ohio Ecological Food and Farm Association (OEFFA) Conference


OSU Extension Bi-Weekly Fruit & Vegetable Report – September 15th, 2023

The OSU Extension Fruit & Vegetable Report is written/published collectively by OSU Extension staff across the state. 

View a recording of the OSU Extension Bi-Weekly Fruit & Vegetable Report updates below:

Farm Science Review 2023

The Farm Science Review (FSR) is one of the nation’s premier farm shows and one of OSU Extension’s largest, most far-reaching educational programs. The event will be held at the Molly Caren Agricultural Center near London, Ohio on September 19th – 21st. The OSU Extension Fruit & Vegetable Team will be hosting a tent all 3 days that will feature presentations from academic and industry speakers on a variety of topics, including nutrient management, entomophagy, integrated pest management, variety trial results, farm marketing, and more. The OSU Extension Fruits & Vegetables exhibit will be located near the gazebo near the Utzinger Garden (booth 385). We hope to see you there!

Check out the 2023 Farm Science Review Program for further information.

Speaker schedule for OSU Extension Fruits & Vegetables exhibit at FSR 2023. Note: There will also be a presentation by Dr. Marne Titchnell, Extension Wildlife Program Director for OSU,  on wildlife management in fruits & vegetables on Wednesday, September 20th from 1:30 – 2:00 PM.

Purple carrot-seed moth detection

The OSU Plant & Pest Diagnostic Clinic (PPDC) recently received an insect sample that was identified to be purple carrot-seed moth (Depressaria depressana), a known pest of crops in the Apiaceae family. This was the first report of purple carrot-seed moth found in Ohio, though it has been found in neighboring states. The insect feeds on the flower heads of crops like carrot, parsnip, dill, celery, parsley, and more, but it is yet unknown if it will be an economically important pest of these crops in Ohio. Check out the article from PPDC for more information.

Please report any suspected larvae/adults with pictures to entomology@osu.edu or ppdc@osu.edu.

Purple carrot seed moth larvae (top) and adult (bottom). Photo by Iowa State University Extension (top) and University of Wisconsin-Madison Department of Entomology (bottom). 

Crop updates



Downy mildew continues to wreak havoc in cucurbit plantings this time of year. As a refresher, here is a factsheet from Michigan State University on downy mildew mitigation. Powdery mildew pressure is reported to be increasing in southern Ohio. Striped cucumber beetles populations are declining in central/northeast Ohio and transitioning more towards higher numbers of corn rootworm beetles. Western corn rootworm, a look-alike of striped cucumber beetle, also feeds on cucurbits and can impact yield if heavy populations are present. Check out this article from Iowa State University for information on identifying different rootworm beetle pests. 

Virus symptoms are being observed in some melon plantings. There are various aphid-vectored potyviruses that affect cucurbits and they can be hard to differentiate from one another, though control practices are similar for all of them. The big 4 for cucurbit crops are cucumber mosaic virus, papaya ring spot virus, watermelon mosaic virus, and zucchini yellow mosaic virus. Like many crop diseases, management practices are preventative and include using resistant varieties or planting earlier to ensure harvest before viral symptoms appear towards the end of the season. Getting aphids under control may also minimize virus infection to some degree.

Cucumber mosaic virus – symptoms include yellowish-green “mosaic” mottling on foliage or fruit and crinkled leaves. Photo by Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org.

Papaya ringspot virus – symptoms include wrinkled leaves and discolored, bumpy fruit. Photo by Mary Ann Hansen, Virginia Polytechnic Institute and State University, Bugwood.org.


Watermelon mosaic virus – symptoms include wrinkled leaves and geometric patterns on fruit.  Photo by Dorina Pitorac, European Plant Protection Organization.

Zucchini yellow mosaic virus – symptoms include blistered, wrinkled leaves and fruit with discolored bumps. Photo by University of Massachusetts Extension.

Fruiting Vegetables

Late-season aphid feeding is being observed in some solanaceous crops. Honeydew is a sugary liquid secreted by aphids and other sap-sucking insects (whiteflies, spotted lanternfly, etc.). Honeydew accumulation on crop foliage or fruit can lead to growth of sooty mold, which is a term for various genera of fungi that colonize the sticky exudate. Sooty mold does not render vegetables inedible, however, and can be readily washed off. 

Honeydew from aphids (and other sap-suckers) on plant leaves is sticky to the touch and can be colonized by sooty mold. Photos by Kansas State University Entomology (top) and Joe Boggs, the Ohio State University Extension (bottom). 

Regular bouts of rainfall as we head into the fall are leading to increased incidence of Phytophthora infection in peppers (and cucurbits). While excess water is a problem for some vegetable growers in Ohio, some parts of western Ohio still remain abnormally dry, according to the U.S. Drought Monitor. Mites have been a problem in some areas, while thrips have taken a downturn. Keeping mites under control towards the end of the season can reduce the chance of heavy pressure next season by reducing the egg load/number of overwintering adults that will become next year’s mite infestations.


Tree fruits

Early varieties of apples are being harvested across the state. Brown marmorated stinkbug pressure is increasing. Bitter rot is starting to be observed in some orchards. Marssonina leaf blotch is also being seen in some organic orchards, where management can be difficult without the use of fungicides. Removal/destruction of leaves on the orchard floor in the fall can reduce overwintering sites for the pathogen. Black knot is being seen on some ornamental plum trees, so commercial plum and cherry growers should keep an eye out for black knot galls on their trees and promptly remove them if they see them.

Gall of black knot (Apiosporina morbosa), a fungal pathogen of plum, cherry, and other types of fruit trees. Photo by Joseph O Brien, USDA Forest Service, Bugwood.org.

Small Fruits

Preparing Brambles for Winter – Sanitation Practices for Disease Prevention
Melanie Ivey, State Fruit Pathologist and Fresh Produce Safety Specialist, The Ohio State University

Disease management of perennial fruit crops is a year-round endeavor. Many fungal pathogens survive the winter months in the soil or plant debris, infected canes or buds, or dead canes. As part of an integrated disease management program fall sanitation practices to reduce inoculum in the planting should be done.  Best sanitation practices include removing floricanes after harvest, removing diseased and dead canes, removing dead or systemically infected plants, and raking or chopping fallen leaves. Pruning debris should be destroyed by burning or placing in the trash or discarding it away from the planting. Diseased plant material should not be composted.  Pruning cuts should be sharp and clean to avoid unnecessary mechanical wounds.

The fall is also a good time to scout for and remove wild bramble populations that are near the production field. In addition to fall sanitation practices, some diseases require a dormant or delayed dormant fungicide application. For dormant or delayed dormant fungicide recommendations consult the Midwest Fruit Pest Management Guide (OSU Extension Bulletin 506).

The table below summarizes where the fungi for several common diseases of brambles in Ohio overwinter, the recommended fall sanitation practices for each disease, and whether a dormant or delayed dormant fungicide application is recommended.

Upcoming Events: 

September 19 – 21, Farm Science Review

September 27, Wooster, OH, Midwest Mechanical Weed Control Field Day

September 30, Albany, OH OEFFA CSA Veggie Farm Tour

December 5th – 7th, Grand Rapids, MI, Great Lakes Fruit, Vegetable, & Farm Market Expo 

January 15 – 16, Columbus, OH, 2024 Ohio Produce Network

February 15 – 17, Newark, OH, 2024 Ohio Ecological Food and Farm Association (OEFFA) Conference

OSU Extension Bi-Weekly Fruit & Vegetable Report – July 7th 2023

The OSU Extension Fruit & Vegetable Report is written/published collectively by OSU Extension staff across the state.

Air Quality

With the recent poor air quality caused by wildfire smoke, questions were filtering into county offices regarding potential effects on crops. One of the major potential concerns is ozone damage to plant tissue if there are significant concentrations in wildfire smoke. Check out this article from University of Minnesota Extension for more information.

A question came in from the community asking if the smoke from the Canadian wildfires would affect the ability to eat lettuce from their garden. Information from Jennifer Little, Family and Consumer Sciences Extension Educator in Hancock County, cited that according to the Environmental Protection Agency (EPA) and the United States Department of Agriculture (USDA) that there should not be any issue with consuming the lettuce. Folks can follow normal harvesting/cleaning processes prior to consuming vegetables. Any harm to humans would be from breathing the smoke-filled air, which could cause respiratory issues. Therefore, the concern is not in consuming the lettuce but in spending time outdoors. It is wise to take precaution with the amount of time you are spending outside when air quality is poor, especially if you have underlying respiratory issues. More information on air quality can be found on the Ohio Department of Health’s website.

Crop updates



A number of insect pests are being found in bean plantings, including Japanese beetles, Mexican bean leaf beetles, and potato leafhopper. Aphids have also been found in beans, as they have been found in many other crops this year. With the extremely elevated number of aphids, there has been ample opportunity for natural enemies such as predatory and beneficial insects to also build their populations. Species such as lady beetles, predatory stink bugs, and parasitic wasps are being found in abundant numbers. Signs of natural enemy activity include “aphid mummies”, which are the remains of aphids resulting from parasitic wasps laying their eggs in the insect. When the eggs hatch, the wasp larvae consume the host from the inside, leaving behind only the dried outer shell of the aphid.

Aphid mummy present in an alfalfa field. Photo by Frank Becker, OSU Extension.


  Cross-striped cabbage worm is being detected in eastern Ohio. Check out this article from Kansas State for a quick primer on this insect pest. 


  Striped cucumber beetle pressure is sporadic across Ohio, with some farms showing high populations and levels of damage while others show very little. Even plantings where the Farmore FI400 (thiamethoxam) seed treatment was used are showing outsized amounts of feeding. For information on integrated cultural management practices to use, check out this article on non-chemical striped cucumber beetle control.

Squash vine borer (SVB) egg laying is underway. Check out this article from Michigan State University Extension on SVB biology and control to learn more about the pest’s life cycle. Squash vine borer is one of the many insect pests that OSU Extension’s IPM program traps throughout the growing season to monitor population spread and density. For more information on how to use trapping to monitor this pest, check out this instructional video from the OSU IPM program

  Mice and vole feeding on young cucurbit seedlings this year has been severe and exacerbated by the dry weather. Wildlife damage in fruits and vegetables persists as a problem for which there are no surefire solutions. Tactics for preventing wildlife damage include employing netting, fencing, repellants, trapping, and other lethal/non-lethal deterrents. Resources include the Ohio DNR Nuisance Animal Control Manual and Wildlife Management Factsheets from the USDA/Michigan State University Extension.

Root crops 

High thrips populations are currently being observed in maturing onion crops.

Both homeowners and commercial garlic growers alike have been impacted by garlic bloat nematodes this growing season. This pest will damage other plants in the allium family as well, including onions, chives, and leeks. Some of the symptoms we see resulting from damage caused by garlic bloat nematodes are stunted leaf growth, distortion, yellowing, wilting, and premature dieback of the leaves, as well as bulbs that can look rotten since the damage opens up the plant tissue to be infected by other bacteria and fungi. As shown in the pictures (below), the roots can be partially or completely missing.

Garlic bulbs showing damage caused by garlic bloat nematode. Photos by Thomas Becker, OSU Extension

The best thing that garlic growers can do to prevent future crops from being infested is to rotate out of alliums and to use fresh seed every year. Mature, reproductive nematodes can live in the bulbs both during the growing season and while in storage. Growers that use saved seed from the previous year’s crop are risking re-infestation. Crop rotation is encouraged for many vegetable crop species to help break pest and disease cycles.    

Colorado potato beetles are being sighted, primarily in organic and volunteer potatoes. Refer to the Midwest Vegetable Production Guide for chemical options for Colorado potato beetle control. 

Tuber quality in potatoes can be impacted by a number of variables over the course of a growing season. Specifically, tuber formation can be impacted by management factors like planting depth and hilling intensity- learn more in this recent article from Matt Kleinhenz of OSU Extension.

Potato flowering signals the start of tuber bulking period. Photo credit, Chris Galbraith, OSU Extension. 

Sweet corn

First plantings of sweet corn around both Huron and Seneca Counties were wiped out by Spring frosts, with later plantings expected to have low yields from both frost damage and heat/drought. Corn earworm is being caught in traps near sweet corn plantings, while European corn borer catches are low. 


Tree fruits

  Despite the dry spring, the pome and stone fruit crop is looking good for the season. Sporadic hail storms near the end of June have caused some damage in apple orchards, as well as to other crops. 

Small fruits

Blueberry u-picks in southern Ohio have opened up to the public. Late frosts in north-central Ohio killed most strawberry blossoms in both matted-row and plasticulture systems, leading to a drastically reduced crop.

Gary Gao, OSU professor and small fruit specialist, received a few messages about the collapsing of blackberry floricanes before fruits reach full maturity. Miki and John Pringle sent him a few pictures of the dying canes. They said that the affected canes turned white and died. The problem was not widespread on their farm. The Pringles grow their blackberry bushes on a rotatable cross arm trellis (RCA). The plants had winter protection with row covers when most parts of Ohio experienced the low temperatures in December 2022. However, it was still possible that some spots of the blackberry patch were not protected well due to holes in the row cover and weaker bushes. 

Gary attributed this problem to blackberry cane blight triggered by cold injuries. Cane blight is a fungal disease. Growers who grow blackberries on RCA are encouraged to put on a dormant spray like Sulforix before they cover the blackberry plants with row covers in December. This is probably the reason that Pringles only saw this problem on some bushes. Growers who grow blackberry bushes in a traditional hedge row without winter protection are not as lucky. Cold injuries induced cane blight are showing up around late June and early July. The affected canes will completely collapse before fruits ripen. It is very disheartening to see since growers invested a lot of time and money on managing the canes. This is why the use of Rotatable Cross Arm trellis with 3 oz. row covers is recommended if growers desire consistent production year after year. 

Collapsing blackberry floricanes from cold injuries and possibly cane blight. Photo by John and Miki Pringle, Pringles Orchard, Goshen, Ohio.

A good way to assess the damage from cold temperatures is to cut the bark to see if the cambium tissue is healthy. Healthy cambium looks light green while dead cambium is dark brown. The ideal time for doing this is April. By then, growers can determine if it is worth all the time and expenses to manage the bushes. If the cambium tissue of the floricanes is damaged and the damage is widespread, growers may elect to cut out all of the damaged canes in April and call it a total loss. 

Floricanes with light green healthy cambium tissue. Photo by Gary Gao, The Ohio State University. 

Blackberry floricanes with dead cambium tissue. Note the dark brown area between outer epidermis or the bark and the xylem or the woody tissue in the middle of the cane. Photo by Gary Gao, The Ohio State University.

Blueberry and Raspberry Harvest Update: Blueberry and raspberry harvest is in full swing in early July. Most blueberry and raspberry growers do pick your own. The crops look quite good despite all of the weather challenges with cold temperatures in December 2022, warm winter, and a drought in spring. It is nice to see rain across Ohio. If you did not see much rain in your area, it is very important to irrigate the bushes to keep plants health and make the fruits grow. 

Ripe Bluetta Blueberry ready for harvest. Photo by Gary Gao, The Ohio State University.


For more information or if you have questions, please reach out to a member of the Fruit & Vegetable team or your county extension educator.


Upcoming Events: 

July 12, 10:00 am – 2 pm, Ontario AgRobotics Field Tour, Part 2

July 20, 9:00 am – 1:30 pm, In-Field and Edge-of-Field Conservation Practice Field Day

July 20, 8:30 am – 3:30 pm, “Climate Smart: Farming with Weather Extremes” conference

August 23, 8:00 am – 4:00 pm, Agriculture Technology Field Day

August 24, 5:30 – 8:00 pm, Western Ag Research Station Pumpkin Field Day

September 19 – 21,  Farm Science Review

September 27,  Midwest Mechanical Weed Control Field Day

December 5th – 7th,  Great Lakes Fruit, Vegetable, & Farm Market Expo 

January 4th – 5th, Ohio Organic Grain Conference


Ohio Fruit News

Ohio Fruit News (OFN) was developed by a team of The Ohio State University small fruit and tree fruit State Specialists, Extension Educators and staff, with support from The Ohio Vegetable and Small Fruit Research and Development Program and the Department of Plant Pathology-Fruit Pathology Program.  Ohio Fruit News provides fruit growers with the most current and relevant information for managing diseases, insect pests and weeds affecting all fruit crops produced in Ohio.  To subscribe to the newsletter please contact Melanie Ivey at ivey.14@osu.edu or 330-263-3849.

The March issue of Ohio Fruit News is now posted (and attached).  Thank you to all the contributors this month!

Online at: https://u.osu.edu/fruitpathology/fruit-news-2/


Spotted Wing Drosophila Spotted

Spotted-wing Drosophila (SWD) is one of the major pests of cane berries, blueberries, black berries, strawberries and peaches. Last week it was detected in Greene, Monroe, Geauga and Wayne counties but likely is present and active in most Ohio counties at this point in the season (https://u.osu.edu/jasinski.4/pestvisualization/#linki).

Spotted wing Drosophila male (L) and female (R).

Recall that this pest is relatively new to Ohio, first discovered in 2011, and has the distinction from other drosophila flies of being able to attack whole, healthy fruit as they begin to blush and ripen.

The best way to monitor for this pest on your farm is to use a trap with either a commercial lure or apple cider vinegar as a bait.

Spotted wing drosophila baited Scentry trap.

If you do this, it will be necessary to empty the trap weekly and look through the catch to identify the male (with the spot on its wing) or female (which has an enlarged serrated ovipositor) using a stereoscope. Remember that the threshold for this pest is 1 SWD fly, male or female. Once the threshold is exceeded, trapping can be halted. This can be a fairly intensive endeavor but has been described in detail in various videos posted to the OSU IPM YouTube channel (setting up trap, identification, salt water tests, etc.). https://www.youtube.com/playlist?list=PL0HRPaZDLHyFqKGmNic832l0SWqMO8IQ4

If you choose not to monitor for this pest and have had SWD on your farm before, it is nearly 100% certain they will return once fruit is in the blush or ripe stage, so you should prepare to manage based on their assumed presence. A fact sheet on SWD giving more detail on management and biology with an up to date list of insecticides can be found here: https://cpb-us-w2.wpmucdn.com/u.osu.edu/dist/1/8311/files/2020/11/SWD_Ohio_handout_V20.pdf

Once you decide to stop harvesting in a certain block, insecticide treatment for SWD can be halted. For smaller or organic growers, some cultural methods including use of black mulch, pruning and netting have been shown to reduce and delay infestation.

Medina County grower talking about his exclusion netting project to manage SWD.

Spotted-wing Drosophila still active on small fruit

Although we are moving toward the end of the season for most small fruit producers, keep in mind that spotted-wing Drosophila populations remain high across the state where traps have been placed on farms. Because of their short life cycle and abundance of ripe fruit, expect these populations to increase up until the first significant frost/freeze event.

SWD larvae in fruit

For growers who have abandoned their small fruit plantings for this year, SWD adults can easily be seen buzzing around ripe fruit as they oviposit eggs beneath the soft skin. Evidence of infestation can be readily seen as soft juicy fruit are filled with white SWD larvae. Even for growers who have maintained a regular spray schedule to control this insect, SWD adults can still be detected flying around bramble and blueberry patches albeit in lower numbers.

Since the threshold for this pest is only one adult per trap, it is necessary to maintain a spray schedule as long as the farm intends to harvest fruit. Once the decision has been made to end harvest, the sprays can be halted.

New Strawberry Disease in Ohio?

A new strawberry disease has been found in Indiana and researchers are looking fo

New strawberry disease symptoms on foliage.

r samples to determine the extent of the problem. The disease, caused by a species of the fungus Neopestaltiopsis, has been reported in several southeastern states and other countries where it causes leafspots, fruit spots and a plant decline. In Indiana, the disease has been reported to cause a leafspot (Figure 1) and a plant decline. This disease resembles Phomopsis and upon further investigation may ultimately turn out to be Phomopsis.

Researchers are asking commercial growers who believe that they may have observed the disease to contact the Purdue University Plant and Pest Diagnostic Clinic (ppdl-samples@groups.purdue.edu​ or 765-494-7071). The PPDL will waive sample handling fees for these samples until the researchers obtain the desired number of samples for the survey. Updates will be posted to the Hotline and to the PPDL website. Samples from multiple strawberry varieties and different types of production fields (matted row, plasticulture, high tunnel) are encouraged.

Information required for each sample:

  1. Strawberry variety
  2. Growing method: Matted row or plasticulture
  3. Location (state and county) where grown
  4. Approximate date of planting or year of matted row culture.
  5. Symptoms observed: Leaf spot, fruit rot, crown rot, or a combination of these.

This research will attempt to determine where the disease exists in Indiana and how the disease may be controlled. Results of these studies will be reported here when completed. The North American Strawberry Growers Association is sponsoring this research.

Stink Bugs on My Mind…and Camera

Overwintering BMSB getting active inside house.

While sitting at my home office desk this rainy afternoon, an annoying BMSB adult started buzzing around my head, landed on the window and then flew to the door, a subtle reminder to write this brief article. Earlier this week I was able to get out and shoot a quick video about identifying, monitoring and managing Brown Marmorated Stink Bug (BMSB). If you are interested to learn the current details of how to trap for this pest, take a look at the final video on the OSU IPM YouTube channel (https://youtu.be/PVtY-c92ZdM).

Distribution of BMSB based on trapping network in 2019.

While BMSB has an appetite for most fruit and vegetable crops plus corn, soybean and other hosts, it generally has not developed into a significant pest in Ohio as in states further east and into the mid-Atlantic region.  Our efforts to monitor this pest over the years has evolved with new trap designs and aggregation lures. The results of our monitoring seem to suggest the pest is slowly increasingly in the central, southwest and eastern areas of the state.

Sticky panel trap with pheromone lure.

While BMSB is beginning to become active now, most of the damage can be expected in the summer months on green and ripe fruit. In August and September, BMSB becomes more mobile and is attracted to sticky panel traps baited with pheromone lures. Unfortunately, the only crop with a threshold using the sticky panel traps is apples. For each apple block (ca. 5A) place one baited sticky trap at the edge and one in the interior about 50m away; when either trap catches 4 or more BMSB adults or nymphs, a treatment may be justified. Since BMSB tends to be an edge pest, a perimeter spray may be an effective way to treat this pest instead of the entire orchard.

For other crops, place a trap at the field edge, interior of the field or near a wooded border that is adjacent to a crop field to get an early determination if BMSB is in the area. One of the goals of current BMSB research is to develop more thresholds for other crops to help guide management decisions. Until then growers will have to resort to frequent scouting for nymphs an adults of BMSB and several other pest stink bugs in their crops.

Dr. Celeste Welty has much more information related to identification, biocontrol, damage and treatment of BMSB on her website (https://u.osu.edu/pestmanagement/pests/bmsb/). Additional information can be found at https://www.stopbmsb.org.

Be on lookout for thrips on strawberries

Thrips can be a serious pest of strawberries, but they are an occasional pest. This means that in most years, they are not a problem, but in some years, they can be a big problem. The reason for variability from year to year seems to be related to weather systems. In some years, conditions are right that large numbers of small insects such as thrips and leafhoppers blow into Ohio on weather fronts from the southern USA during the time that strawberries are in bloom. In other years, this long-distance movement does not happen at all, or happens later, at a time when strawberries are no longer in bloom. Due to the irregularity in the occurrence of thrips, it is a pest that is well suited to weekly scouting, for early detection of any infestation.

Strawberry fruit that have been injured by thrips are a dull or bronzed color, and are often small, hard, seedy, and fail to ripen (Figure 1). Thrips can cause uneven maturity of fruit. When thrips are abundant and the berry injury is severe, the result can be a strawberry crop that is completely unmarketable. Diagnosis of thrips injury can be tricky because thrips are not the only cause of fruit bronzing. Bronzing can be due to feeding by cyclamen mite or two-spotted spider mite, or to infection by powdery mildew, or to occurrence of low temperatures or hot dry winds, or to pesticide spray effects.

Thrips are often overlooked due to their small size and their tendency to hide in protected places. Thrips are weak fliers but fast runners. Thrips are small, slender, elongate, ‘cigar-shaped’ insects (Figure 2), about 1 mm (1/25 inch) long as adults. They differ from other insects by having narrow strap-like wings that are fringed with hairs. The wings are usually folded lengthwise over their back when they are resting or feeding. The immature thrips are the same shape as adults but smaller and without wings. Thrips have lopsided mouthparts that have a well-developed left mandible and an underdeveloped right mandible. They feed by piercing and scraping plant cells with the mandible then sucking sap that oozes out of the punctured cells.

The thrips species that most commonly infests outdoor strawberries is Frankliniella tritici, which has the official common name of ‘flower thrips’, but which is widely known as the ‘eastern flower thrips’. The adults are yellowish brown, and the immatures are whitish-yellow. The eastern flower thrips does not tolerate cold weather, so does not survive winter well in places like Ohio. The eastern flower thrips has a wide host range that includes many flowering weeds, where the thrips population can build up before moving into a cultivated crop like strawberries.

The eastern flower thrips looks quite similar to three other species of thrips that inhabit Ohio and have been reported from strawberries: the western flower thrips (Frankliniella occidentalis), the tobacco thrips (Frankliniella fusca), and the onion thrips (Thrips tabaci). The western flower thrips is the species commonly found in greenhouses; it is generally much more difficult to control than other thrips because it is usually resistant to most insecticides. In greenhouses, the western flower thrips causes injury to tomatoes, peppers, and cucumbers as well as to strawberries. The onion thrips is best known as a serious pest of dry bulb onions, green onions, and cabbage but is sometimes found on other crops.

Thrips generally prefer to feed on flowers rather than other plant parts, but they can feed on leaves and fruits. On strawberries, the infestation starts by adult thrips being attracted to flowers, and the female inserts eggs at the base of flowers. Each female can lay about 80 eggs. Infestation can continue during fruit set by adults and their immature offspring. Thrips feed on pollen, seeds, and the fruit tissue between seeds. Thrips hide under the cap of the berry or in grooves around the seeds on the berry.

A key to thrips management is frequent monitoring by scouting, at least once per week. Growers should designate one person on the farm to be sure that scouting is done every week. Where multiple varieties are present, each variety should be scouted separately. The scout should begin the season by examining early flower clusters on early cultivars, as soon as the first blossoms open. Scouting should be done in five different areas within small fields or in ten different areas within large fields. In each area, 10 blossoms should be tapped into a white cup, or into a zip-top sandwich bag, which should then be examined for the dislodged thrips running around on the surface. Count the number of thrips found, then calculate the average number of thrips per blossom. The action threshold for treatment with insecticide, used the midwestern USA, is the presence of 2 or more thrips per blossom. This is a conservative threshold that is lower than a threshold of 10 thrips per blossom that is used in some mid-Atlantic and California regions.

Scouting should continue after fruit set, until fruit are ½ inch diameter, by examining 50 fruit in each area, and counting thrips on those fruit. Fruit can be examined in place, or removed and put in a plastic zip-top bag, which can be placed in a sunny location so that the heat forces the thrips to leave their hiding spots and begin running around on the bag surface. Once fruit are ¼ inch in diameter, an action threshold is 0.5 thrips per fruit.

If thrips are above threshold, the trickiest part of management is to avoid spraying insecticide that will harm pollinators. Insecticide should not be applied during bloom, to protect bees and other pollinators. Insecticide should be applied pre-bloom or before 10% of the plants have open blossoms. If thrips are found above threshold on early cultivars, then a preventive spray can be made on the later cultivars before their flowers open, to avoid harming pollinators. If insecticide is needed during bloom, it should be applied in the evening when bees are least active. Sprays targeted at tarnished plant bug or spittlebug or strawberry clipper weevil, just before bloom, often do a good job of controlling any thrips that also are present.

Insecticides used to manage thrips on conventional strawberries include several products that are labelled for control, and several that are labelled only for suppression (Table 1). Products for control of adult and immature thrips are Radiant, Assail, Apta, and Dibrom, all of which have thrips listed as a target pest on their labels. Note that use of Apta on strawberries appears on a supplemental label, not the federal label. A product for control of immature thrips, but not adults, is Rimon. Products for suppression of thrips are Closer, Exirel, Sivanto, Transform, and Verdepryn. In addition, there are several products that are allowed for use on strawberries, but that do not list thrips as a target pest on strawberry, however thrips are a target pest of these products on other crops; these are Admire Pro, Agri-Mek, Brigade, Danitol, Harvanta, Lorsban, and Malathion. Note that Lorsban has a 21-day pre-harvest interval thus is for use only pre-bloom. Beware that pyrethroid insecticides such as Brigade and Danitol are no longer as effective as they were in the past due to the development of resistance in thrips populations at many locations. An adjuvant that can be helpful in control of thrips is Wetcit, which is a penetrant, spreader, and wetting aid.

Products for thrips control on organic strawberries are Entrust, azadirachtin products such as Neemix and Aza-Direct, and the beneficial fungus Beauveria bassiana, as well as other natural products (Table 2).

An important natural enemy of thrips is the Orius predatory flower bug, which is a very small true bug that preys on thrips adults and thrips larvae. Orius insidiosus is a common species in Ohio on many crops; it is frequently found on the moist fresh silks of sweet corn and on flowers of Queen Anne’s lace. There are also several species of predatory mites that prey on thrips. The local population of these natural enemies is often inadequate to suppress thrips, but growers who would like to take a biological control approach to thrips management can purchase natural enemies from commercial insectaries: Orius (predatory flower bugs), and four species of predatory mites: Ambylseius swirskii, Neoseiulus (Amblyseius) cucumeris, Amblydromalus limonicus, and Stratiolaelaps scimitus (formerly Hypoaspis miles). Beneficial nematodes such as Steinernema feltiae are another option. Some suppliers of these natural enemies are IPM Labs, Koppert, BioBest, and Rincon-Vitova. Biocontrol is not feasible to begin once the thrips population is large, but can be planned in advance at locations that have a consistent problem with thrips.

-Celeste Welty, Extension Entomologist


Beware of thrips!

The current hot, dry weather can be conducive to outbreaks of thrips. Thrips are very small, slender, elongate, cigar-shaped insects, about 1 mm (1/25 inch) long. They differ from other insects by having thin strap-like wings that are fringed with hairs. The wings are usually folded lengthwise over the back when they are resting or feeding, as shown in the image below. They have asymmetrical mouthparts that have a well-developed left mandible and an underdeveloped right mandible. They feed by piercing plant cells by the mandible then sucking sap that oozes out of the punctured cells.

Smaller, tan thrips on left is the onion thrips (Thrips tabaci). Larger yellowish thrips on the right is the western flower thrips (Frankliniella occidentalis).
Photo by Alton N. Sparks, Jr., University of Georgia, Bugwood.org

Thrips generally have flowers as their preferred plant part but they also feed on leaves and fruits. They are found in flowers of many ornamental plants but also on various vegetables and fruit crops, including tomatoes, peppers, and cucumbers. Thrips are often overlooked due to their small size and their tendency to hide in protected places. When present at low density, thrips are usually not harmful to crops, but when they reach higher density, they can feed on the surface of fruits and cause injury.

The thrips species that infests many outdoor crops is Frankliniella tritici, which has the official common name of ‘flower thrips’, but which is widely known as the eastern flower thrips. The thrips species that is most common in greenhouses is the western flower thrips, Frankliniella occidentalis, which is generally much more difficult to control than other thrips because it is not highly susceptible to most insecticides. A third common species is the onion thrips (Thrips tabaci), which is a serious pest of dry bulb onions and green onions as well as cabbage.

Natural enemies of thrips are Orius flower bugs, which are very small predatory true bugs that prey on thrips as adults and nymphs. Orius insidiosus is a common species in Ohio that is frequently found on the moist fresh silks of sweet corn and on flowers of Queen Anne’s lace. There are also several species of predatory mites that prey on thrips.

Insidious flower bug (Orius insidiosus) feeding on an insect egg.
Photo by John Ruberson, Kansas State University, Bugwood.org


Orius bug feeding on a thrips.
Photo by Robert Webster / xpda.com / CC-BY-SA-4.0 via Wikimedia Commons.

Thrips can be monitored by shaking flowers over a paper or into a cup or zip-top sandwich bag, which should then be examined for the dislodged thrips running around on the surface. Action thresholds have not been developed for most crops, but on strawberry we use a threshold of 2 thrips per flower.

In the past, pyrethroid insecticides provided control of thrips, but there are widespread observations that pyrethroids are no longer very effective for thrips control at most locations. Newer insecticides used to control thrips on conventional crops include Radiant, Assail, and several others, as shown in Table 1 below. Products for thrips control on organic crops include Entrust and various others as shown in Table 2 below.

If a biological control approach is preferred, natural enemies are available for purchase from commercial insectaries for thrips control: Orius (predatory flower bugs), and two species of predatory mites: Amblyseius cucumeris and Ambylseius swirskii. Beneficial nematodes such as Steinernema feltiae are another option. Microbial options include sprays of the beneficial fungus Beauveria bassiana, which is found in several commercial products. Biocontrol is not feasible to begin once the thrips population is large but can be planned in advance at locations that have a consistent problem with thrips.

-Celeste Welty, Extension Entomologist