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 (

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 ( Additional information can be found at

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


Reflex and other herbicide thoughts for Pumpkin and Squash

Thinking about weed control.

It’s the second week of April and if you grow either pumpkin or squash, the notion of weed control has undoubtedly been on your mind. On May 29 2020, Reflex herbicide (fomesafen, Syngenta) was given a 24(c) label (local needs exemption) in Ohio for use on cucurbits.

What does Reflex bring to the weed control game to complement other currently labeled herbicides? Reflex is a pre-emergent herbicide which should be applied after seeding but before crop emergence. The primary fit would be against small seeded broadleaves such as lambsquarters, purslane, common ragweed, nightshade and pigweeds (see full efficacy chart here

As always, choose fields with low weed pressure if possible and start with a relatively clean field either through stale seed bed or use of burn down herbicides (glyphosate, paraquat). Use pre-emergent herbicides followed by post emergent herbicides if necessary to get weed control further into the season, then mop up with spot sprays as needed. The full list of herbicide options can be found in the 2021 Midwest Vegetable Production Guide pg. 102 (

Tony Dobbels discussing Reflex on pumpkins.

In July 2020, members of the department of Hort and Crop Science and IPM Program put out a small late summer herbicide weed screen trial at the Western Ag Research Station which was reported extensively in the 2020 virtual field day video segment starting at the 10:01 mark ( In this 16 minute video, Reflex alone plus combinations of Reflex with Dual II Magnum, Sandea and Strategy are shown and discussed.

There is a Vegblog post on June 16, 2020 with additional comments about this herbicide concerning direct seeded and transplanted pumpkin and squash (

Symptoms of herbicide injury.

Be sure to read the entire Reflex 24(c) label and understand the warnings about its use:
– Needs 0.5-1” rain or irrigation to be activated
– Sensitivity is possible on both pumpkin and squash hybrids – test on small area first
– Butternut is very sensitive to Reflex – test on small area first but expect thinning or yield reduction
– Cold and wet soils during germination and seedling growth may result in delayed maturity and / or yield.
– Heavy rain shortly after transplanting may also result in delayed maturity and / or yield.
– Reflex herbicide rates below 1 pt/A are not intended to be used as a stand-alone weed control program and should be used with other herbicides and/or other methods of weed control that support weed resistance management.
– Carryover injury possible and beware of rotation restrictions

The research and demonstration behind these new uses was paid for in part by the IR-4 Program, the Ohio Vegetable and Small Fruit Research and Development Program (OVSFRDP), and the IPM Program, and could not be conducted without the OARDC research stations and support from the chemical companies.

What plans are in store for 2021? We have another herbicide screening trial that will be rated for percent control of weeds and a hybrid sensitivity trial where we will look at potential seedling emergence and injury on pumpkin, squash and butternut as described by the label warning.

How Do You Maintain the Health – Quality – Productivity of Soils in Your High Tunnel(s)?

Growers are increasingly impacted by and/or interested in learning how to prevent declines in the health, quality, or productivity of soils in their high tunnels. More are experiencing or aware that various biotic and abiotic issues threaten crop yield and quality and farm income. As some have learned, increases in nematode populations, disease inoculum, salinity, nutrient deficiencies/excesses/imbalances, and/or compaction or reductions in soil structure can be troublesome. Thankfully, a comprehensive effort is underway to help understand and address soil health/productivity-related challenges in high tunnel production. Sponsored by the USDA Specialty Crops Research Initiative and coordinated by Dr. Krista Jacobsen of the University of Kentucky, researchers with different expertise and extension specialists are documenting grower concerns and practices and charting a path leading to greater grower success. The OSU and five other universities are also currently involved. Team members recently hosted a focus group of eight growers from the Great Lakes (including Ohio) and will hear from more in other regions soon. Growers in the recent focus group represented a range of experience, size of operation, crops grown, typical number of annual production seasons (1-4), and overall farming approach (conventional, organic). Collectively, they shared concerns with issues referenced earlier and gave special attention to others such as the effects of high tunnel soils going extremely dry fall-to-spring unless watered (with or without also being cropped). Interestingly, this observation and concern lines up with the view shared by Dr. Bruce Hoskins of the University of Maine that high tunnel production is like “irrigated desert production in the west and southwest,” and that “failing to realize or take steps to address potential problems because of this” can be detrimental (see VegNet article Feb. 20, 2021). In any case, the recent conversation with growers was a reminder of: (1) potential causes of declines in (high tunnel) soil productivity (examples are listed below), (2) innovative steps growers and researchers are taking to limit the problem, and (3) benefits of addressing the complex problem through partnerships. It also prompted me to ask myself what I am doing to maintain the productivity of soils in my high tunnels. Maybe it will do the same for you!

The health-quality-productivity of soils used in vegetable production, including in high tunnels, can decline for many reasons. Some major ones are listed below in no particular order.

1. Repeated or excessive use of a potentially narrow range of fertilizers, various chemicals, and other soil amendments.
2. Vegetable plants often having relatively small and shallow root systems (compared to other annual crops) and crops returning relatively little residue to the soil.
3. Short rotations with few crops.
4. Placing frequent pressure on and aggressively disturbing soil, especially when it is wet.
5. In high tunnels, relatively unique and potentially extreme temperature and moisture profiles.


This article was submitted by Dr. Erdal Ozkan
Dept. of Food, Agriculture and Biological Engineering

Pesticides need to be applied accurately and uniformly. Too little pesticide results in poor pest control and reduced yields, while too much injures the crop, wastes chemicals and money, and increases the risk of polluting the environment. Achieving satisfactory results from pesticides depends heavily on five major factors:

  1. Positive identification of the pest.
  2. Choosing the least persistent and lowest toxicity pesticide that will work.
  3. Selecting the right equipment, particularly the right type and size of nozzle for the job.
  4. Applying pesticides accurately at the right time.
  5. Calibrating and maintaining equipment to make sure the amount recommended on the chemical label is applied.
sprayer calibration

Proper calibration is key.

Inspection of sprayers

Higher pesticide costs and new chemicals designed to be used in lower doses make accurate application more important than ever. There is no better time than early spring to take a closer look at your sprayer. Here are some of the things I would recommend you do this week if you don’t want to unexpectantly halt your spraying later in the season when you cannot afford delaying spraying and missing that most critical time to control weeds:

  • First, if you need new or one other type of nozzles on the boom this year, do not delay purchasing new nozzles. Do it now.
  • Double-check your sprayer for mechanical problems before you start using it. You won’t have time to do this when planting is in full swing.
  • Clean the sprayer tank thoroughly and make sure all filters on the sprayer, especially the nozzle filters are clean.
  • Clean spray nozzles to make sure they are not partially plugged. Check their flow rates, and replace the ones that are spraying more than 10 percent of the original output at a given spray pressure.
  • Check the agitator in the tank to make sure it’s working properly. This is extremely important if you will be applying dry chemicals. Run water through the spray system to make sure everything is working properly.
  • Always carry a spare, excellent quality pressure gage (glycerin filled) in your shop, and check the accuracy of the pressure gage on the sprayer compared to the reading you see on this spare pressure gage. Your rate controller will not know if your pressure gage is bad, and the flow rate of nozzles will be adjusted by the rate controller using the bad pressure gage.
  • Once you are convinced that all sprayer parts are functioning properly, it is time to calibrate the sprayer.

Calibrate the sprayer

One can determine if the chemicals are applied at the proper rate (gallons per acre) only by carefully calibrating the sprayer. Calibration, perhaps more than anything else, will have a direct impact on achieving effective pest control and the cost of crop production. While applying too little pesticide may result in ineffective pest control, too much pesticide wastes money, may damage the crop and increases the potential risk of contaminating ground water and environment. Results of “Sprayer Calibration Clinics” I participated in Ohio a while back, and data from several other States show that only one out of three to four applicators are applying chemicals at a rate that is within 5 % (plus or minus) of their intended rate (an accuracy level recommended by USDA and EPA). For example, if your intended rate is 20 gallons per acre, the 5% tolerable difference will be 1 gallon (5% of 20). So, your actual application rate should be as close to 20 gpa as possible, but not outside the range of 19 to 21 gpa.

How do you calibrate the sprayer?

There are several ways to calibrate a sprayer. Regardless of which method you choose, you will end up measuring the nozzle flow rate (in ounces), and the actual travel speed in miles per hour to determine the actual chemical applied in gallons per acre. Once you determine the actual application rate, you should find out if the difference between the actual rate and the intended rate is greater than 5% of the intended rate (plus or minus). If the error is greater than the 5% tolerable error margin, you will need to reduce the error below 5% by doing one of three things: 1) Change the spraying pressure, 2) change the travel speed, and 3) change nozzles (get a different size) if the error cannot be reduced below 5% by making adjustments in either the pressure or the travel speed, or both.

It usually doesn’t take more than 30 minutes to calibrate a sprayer, and only three things are needed: a watch or smart phone to record the time when measuring the nozzle flow rate or the travel speed, a measuring tape, and a jar graduated in ounces. Please take a look at the Ohio State University Extension publication FABE-520 for an easy method for calibrating a boom-type sprayer.  Here is the URL for this publication:


Can YOU Help Solve the Case of the Missing Pumpkin?

pumpkinPumpkins are a beloved fall crop ushering in all kinds of festive activities such as hayrides, fall festivals and agritainment events at local farms. When you include Halloween and Thanksgiving holidays into the mix, this iconic orb gets plenty of exposure across the state and provides much needed revenue when most other field vegetables are winding down.

But Ohio’s slice of the pumpkin pie has dramatically shrunk in recent years. From 2011-2015, acres planted averaged 6,680 compared to 2016-19 with an average of 3,840 A planted, a 42.3% loss in acres planted and production value according to the Ohio Annual Statistics Bulletin from 2011-20 (Figure 1).

Figure 1. Pumpkin statistics from 2011-2020.

So the question becomes, what caused the loss of nearly 3,000 acres of pumpkin in production years 2016-20? People I have asked about this offer explanations such as Ohio growers are increasingly importing cheap and widely available pumpkin fruit from other states or abroad, saving on production costs. I have also heard that growers may not be reporting their pumpkin acres accurately or at all on National Ag Statistic Surveys which could account for the drop in reported acreage, but likely not so much from 2015 to 2016-2020. Was there a market shift due to buyer demands or Food Quality and Protection Act leading to a mass exodus of growers, again not known.

If YOU have an idea for the loss of 3,000 A of pumpkins from Ohio production, please feel free to share it with me at or call me at 937-772-6014.

If you prefer to leave a written comment of any length, here is an anonymous link where you cannot be identified if that is a concern you have.

If any production issues are mentioned, I’ll be sure to follow up with additional articles in the VegNet Blog to address these.