Soybean Gall Midge: New Pest of Soybean in Nearby States

Producers in Nebraska, Iowa, and South Dakota have been dealing with gall midges in soybean. This is a fly in the family Cecidomyiidae, which is the same family as the Hessian fly, sorghum midge, and several other agricultural pests. We have not confirmed any infestations of this insect in Illinois at this time; the closest confirmed, damaging infestations that I know of are in western Iowa. However, because so little is known about the biology of this insect, producers should learn to identify it in case it does show up in Illinois. The following links to material produced by my colleagues in Iowa and Nebraska contain information on the identification and distribution of this insect pest; if you find any potential infestations within Illinois, please let me know at the contact information below. Happy scouting!



Nick Seiter (217) 300-7199

Research Assistant Professor, Field Crop Entomology

Ewing Demonstration Center Celebrates 50 years of Continuous No-till Research at Agronomy Field Day on July 26

The University of Illinois Extension will host the Ewing Demonstration Center Agronomy Field Day on Thursday, July 26, 2018 at 9 a.m.  Every growing season presents challenges to production, and this year is no exception!  We are happy to host this summer field day to share with local growers current, ongoing agronomy research in southern Illinois, including cover crop trials on corn and soybeans, nitrogen management in corn, weed management in soybean, and our continuous no-till field, now in its 50th year of continuous no-till production.

We are highlighting our 50th year of continuous no-till production in our field day this year.  This no-till trial area was established in 1969 by George McKibben, the “Father of No-Till”, long-time agronomist and researcher at the Dixon Springs Ag Center in southern Illinois.  This plot has been cropped utilizing no-till production of corn and soybeans ever since.  The “zero-till” system as it was first called, was researched to “save the soil” that was lost over the many years of intensive tillage required to raise grain crops on the sloping hills of southern Illinois with the planting equipment available at the time.

In honor of this milestone, we will have the original “zero-till planter” on display.  This planter was modified and built in the early 1960s at the Dixon Springs Ag Center and used there and also at the Ewing Demonstration Center and other research sites.  The demonstrated success of this zero-till planter and production system was one of the inspirations that led companies like Allis-Chalmers and John Deere to start engineering and producing no-till planting equipment.  Also, joining us for the field day will be Donnie Morris, retired farm mechanic and engineer who built this planter, along with other retired Extension advisors and educators that worked at the Ewing Demonstration Center over the years.


The topics to be discussed at Field Day include:


Looking Back at 50 Years of Continuous No-till

  • Current and Retired Staff, University of Illinois

Insect Management in Corn and Soybean

  • Nick Seiter, Research Assistant Professor, University of Illinois

What We Have Learned After 48 Years of Continuous No-till

  • Ron Krausz, Manager SIU Belleville Research Center
  • Sarah Dintelmann, Undergraduate Assistant ,Weed Science, SIU

Managing Cover Crops in Corn and Soybean

  • Nathan Johanning, Extension Educator, University of Illinois

Intro to Corn Genetics:  Why is Sweet Corn Sweet?

  • Talon Becker, Extension Educator, University of Illinois


Please join us for Agronomy Field Day to help celebrate this milestone in crop production!  The field day is free and open to anyone interested, and lunch will be provided.  Certified Crop Advisor CEUs will also be offered (Soil & Water – 2.0; IPM – 0.5, Crop Management – 0.5).  The Ewing Demonstration Center is about 20 minutes south of Mt. Vernon located at 16132 N. Ewing Rd; Ewing, IL 62836, on the north edge of the village of Ewing, north of the Ewing Grade School on north Ewing Road.  Watch for signs.

To help us provide adequate lunch and materials, please RSVP to the University of Illinois Extension Office in Franklin County at 618-439-3178 by Tuesday, July 24.  For additional information on the field day, contact Marc Lamczyk at the Franklin County office or

Western Corn Rootworm: Adult Sampling and Economic Thresholds

Authors: Nick Seiter, Joe Spencer, and Kelly Estes

Based on degree day accumulations, western corn rootworm egg hatch should be underway in much of Illinois (roughly south of Peoria as of May 29; you can view your specific location using the degree day calculator here: We are probably just over a month away from seeing the emergence of the first adult beetles. With low rootworm populations for the last several years, there has been a renewed interest in adult sampling. The only way to determine if larval densities will be high enough to justify a control action in a specific cornfield next spring is to monitor adults in the field this summer. Doing this correctly will require some preparation to obtain the correct materials. Now is a good time to review your monitoring procedures for western corn rootworm adults.

The most common monitoring tool for western corn rootworm adults is a 5.5 × 9-in yellow card trap coated in sticky material (e.g., Pherocon® AM No-Bait trap, Trécé, Inc., Adair, OK). The yellow color attracts the beetles, and when they land on the sticky substance they become trapped (Fig. 1). We recommend placing 12 of these traps uniformly throughout each field that you are monitoring beginning in late July. If the field you are monitoring is planted to corn this season (i.e., continuous corn), simply place each trap on a corn plant just above an ear. If you are monitoring a soybean field this season that will be rotated to corn next year, you will need to place each trap on a stake so that it will sit just above the soybean canopy. PVC pipes (½” diameter) are a relatively cheap and easy material that you can use to make these stakes, but wooden, metal, or plastic stakes also work.  Use poles that are long enough to allow trap height to be raised as the soybean crop grows taller.  Replace each trap once a week for 3-4 weeks, count all western corn rootworm adults stuck to the trap upon collection, and determine the average number of adults collected per trap per day.


Yellow sticky card trap

Figure 1. Yellow sticky card trap used to monitor western corn rootworm adults.


We recommend using the economic thresholds recently updated by our colleagues at Iowa State University [1] to determine if a control action is needed in corn the following spring (Table 1). If the beetle numbers you see on your traps are above these thresholds, a corn hybrid with Bt traits targeting corn rootworm or a soil insecticide is justified in that field when corn is planted the following spring. While monitoring for western corn rootworm takes some effort, it is the only way to get field-specific information on the economic need for a control tactic the following year.

Table 1. Economic thresholds for western corn rootworm in continuous or rotated corn.

Sticky Trap Location Economic Threshold
Corn (continuous corn) 2 beetles per trap per day
Soybean (rotated corn) 1.5 beetles per trap per day


1.             Dunbar MW, Gassmann AJ. Abundance and Distribution of Western and Northern Corn Rootworm (Diabrotica spp.) and Prevalence of Rotation Resistance in Eastern Iowa. Journal of Economic Entomology. 2013;106(1):168-80.

Black Cutworm: Management Considerations in Corn

With corn planting wrapping up throughout most of Illinois, the time has come to scout for cutworms. While several species of cutworms infest early season corn, black cutworm (Agrotis ipsilon) is the most likely to cause economic damage. We have received a handful of reports of cutting in southern Illinois, with more expected in the coming weeks as heat units begin to accumulate. If you are not doing so already, follow Kelly Estes’s reports on the Bulletin and through Twitter (@ILPestSurvey) for up to date information on black cutworm moth flights and degree-day accumulations. These updates provide excellent guidance on when to expect damage in your part of the state (remember that the predicted dates are a forecast, and are subject to change based on actual temperature accumulations).

A few management points to consider:

  • Infestations are more likely in later planted corn, as delayed planting means larger cutworm larvae are present at earlier stages of corn development.
  • Black cutworm moths prefer to lay their eggs on grasses, not bare ground. Therefore, fields with grassy weeds present at or shortly before planting are more likely to experience damaging populations. Similarly, monitor fields closely if a grass cover crop (e.g., cereal rye) is terminated while corn is susceptible to cutworm damage (emergence to ~V5).
  • The economic threshold for black cutworm is 3% of plants cut with black cutworms still present in the field. Look for plants that look like they have been cut roughly with scissors close to the base (Fig. 1); plants with intact roots (Fig. 2) were most likely dug up by birds and do not represent cutworm damage. Remember, larvae (Fig. 1) do their feeding at night and hide in residue or just below the soil surface during the day, so you will have to do a little bit of digging near the base of the plant to find them.

    Black cutworm larvae and damage

    Fig. 1. Black cutworm larvae uncovered at the base of a cut plant. Photo: Robert Bellm, Crop Advisor

    Bird damage to seedling corn

    Fig. 2. Seedling corn plant uprooted by a bird feeding on the germinating seed. Note that plant has been pulled from the ground with roots intact. Photo: Glenn Studebaker, University of Arkansas

  • Several Bt corn trait packages offer suppression of black cutworm, but these might be less effective under heavy infestations or against later stage larvae. Most pyrethroid insecticides labeled for use in corn will do an excellent job of controlling larvae as a rescue treatment; just remember that they only pay off when an economic threshold has been reached.


Nick Seiter: – Research Assistant Professor, Field Crop Entomologist, University of Illinois Department of Crop Sciences

Black Cutworm Moth Flight Beginning

Soil temperatures and field activity are increasing along with moth migration from the south. Insect traps (figure 1) are out around the state and we’ve been capturing both true armyworm and black cutworm moths for over a week. In fact, we recently had our first significant black cutworm moth flights recorded in Montgomery and Champaign counties (figure 2).  We expect activity to increase with both of these insects over the coming weeks. As both corn and soybean planting progress, we encourage growers to scout emerging fields for the present of insect injury.

Figure 1. Black cutworm and true armyworm traps, Champaign county.

For more complete information about the biology, life cycle, and management of black cutworms, a fact sheet is available from the Department of Crop Sciences, UIUC. Provided below is a brief overview of some key life cycle and management facts concerning black cutworms.

  • Black cutworm moths are strong migratory insects with northward flights commonly observed from Gulf States into the Midwest from March through May.
  • Moths are attracted to fields heavily infested with weeds such as henbit, chickweed, shepherd’s purse, peppergrass, and yellow rocket. Cover crops are also attractive to both armyworm and cutworm.
  • Late tillage and planting tends to increase the susceptibility of fields to black cutworm infestations.
  • Cutting of corn plants begins when larvae reach the 4th instar — with a single cutworm cutting an average of 3 to 4 plants during its larval development.
  • Cutting tends to occur most often during nights or on dark overcast days.
  • Fields at greatest risk to cutting and economic damage are in the 1-to-4 leaf stage of plant development.
  • An early warning sign of potential economic damage includes small pinhole feeding injury in leaves (caused by the first 3 instars).
  • Producers are encouraged to look for early signs of leaf feeding as a potential indicator of cutting, rather than waiting for cutting to take place.
  • Don’t assume that all Bt hybrids offer the same level of cutworm protection. Plants in the 1- to 4-leaf stage are most susceptible to cutting.
  • Cutting of plants earlier than these projected cutting dates is possible — localized intense flights may have occurred and were not picked up by our volunteers.
  • A nominal threshold of 3% cutting of plants has traditionally been used as a point at which growers should consider a rescue treatment.

    Figure 1. Projected potential cutting dates, April 23, 2018.

  • Not all Bt hybrids offer adequate protection against black cutworm damage. Growers should consult the Handy Bt trait table prepared by Dr. Chris DiFonzo at Michigan State University to determine the level of protection provided by their chosen Bt hybrid.


Continue to look for insect updates and weekly trap counts here in the Bulletin along with updates via Facebook and Twitter.


Managing Corn Rootworm Populations in Illinois: Considerations for 2018


Authors: Nick Seiter, Joe Spencer, and Kelly Estes

Rootworm management is a yearly consideration for most corn producers in central and northern Illinois. Western corn rootworm (Fig. 1) is the primary pest species throughout most of the state, but areas in northern IL can experience pest pressure from the northern corn rootworm (Fig. 2) as well. Adult population densities have been low in recent years compared with historical averages, although they did creep up a bit in 2017. The overall reduction in corn rootworm pressure is likely due to a combination of unfavorable weather (or at least unfavorable to rootworm larvae) and widespread adoption of corn hybrids expressing combinations of Bt toxins for rootworm control.

Fig. 1. Western corn rootworm adult. Photo: J. Spencer

Over the last few years, western corn rootworm populations with resistance to Cry3Bb1 and mCry3A (two commonly expressed toxins in Bt corn hybrids) have been documented in Illinois. Research published in 2016 on Iowa1 and Minnesota2 western corn rootworm populations showed that resistance to these toxins also confers resistance to the structurally-similar eCry3.1Ab toxin.  Cross-resistance among these “Cry3” Bt toxins should be expected for Illinois western corn rootworm populations.  Resistance to pest control practices in the western corn rootworm is nothing new; this insect is notorious for developing resistance to control tactics such as insecticides and crop rotation. Part of the concern with these recent developments is that there are relatively few Bt toxins available to combat corn rootworm. Furthermore, all available hybrids with pyramided traits for corn rootworm use either Cry3Bb1 or mCry3A in combination with a second toxin (either Cry34/35Ab1 or eCry3.1Ab). This means that, where resistance is present in the population, there might in fact be at best only one effective toxin at work. (If you have trouble keeping all of these toxins straight, a good resource is the “Handy Bt Trait Table” produced by Dr. Chris DiFonzo at Michigan State University:

Fig. 2. Northern corn rootworm adult. Photo: J. Spencer.

There are steps producers can take to manage corn rootworm and hopefully slow the further development of resistance. The best way to delay resistance to any control tactic is to reduce exposure of the target insect to that tactic in the environment. Specific ways to accomplish this with Bt toxins include:

  • Apply rootworm control (whether in the form of a Bt hybrid or a soil insecticide) only where it is economically justified based on sampling rootworm adults the previous year. If you monitor using a yellow sticky trap, the economic threshold is 2 rootworm beetles per trap per day in corn following corn. For rotated corn, the economic threshold is 1.5 western corn rootworm beetles per trap per day in soybean3. (These thresholds are based on a recent study in Iowa, which recalculated economic thresholds for corn rootworm based on updated crop values and control costs3).
  • Rotating corn with soybean or another non-host crop remains an effective management strategy in the southern portion of the state. While crop rotation is no longer a reliable method to protect first-year corn from western corn rootworm damage in central and northern Illinois, all larvae that hatch into soybean still die, and every acre planted to soybean is an acre where larvae are not being exposed to Bt toxins or soil insecticides.
  • Where monitoring indicates that control is justified in corn, rotate the control measures used from year to year. This means rotating among Bt hybrids with different trait combinations and non-Bt hybrids treated with a soil insecticide.
  • Follow all refuge requirements for any Bt corn hybrids you plant. In many cases, the “refuge in a bag” or “RIB” approach is now used, but check with your seed distributor on specific requirements for your hybrids.

Finally, an important step is to monitor the performance of your control methods. While lodging is often the cue we look out for to identify rootworm damage, keep in mind that (1) corn can take a lot of damage without lodging depending on soil type and weather conditions and (2) plenty of factors other than rootworm damage can lead plants to lodge. The best approach to evaluating rootworm damage is to dig a representative sample of roots in late July and evaluate them for feeding damage: unpleasant work, but necessary if we want to understand the true extent of the damage.  Consider planting a small area or a portion of a row with a non-Bt/untreated hybrid as a check strip. Having an untreated patch in your field will allow you to compare the efficacy of your management tactic vs. the background level of damage where no rootworm protection was used. Finally, if you experience greater damage than expected in Bt corn hybrids in 2018, please let us know at the email address below; your reports will help us to document the status of resistance in Illinois and provide updated information to producers.


Nick Seiter: Research Assistant Professor, Field Crop Entomologist,University of Illinois Department of Crop Sciences

Joe Spencer: Principal Research Scientist and Research Program Leader in Insect Behavior, University of Illinois, Illinois Natural History Survey
1Jakka, S.R.K., et al. Scientific Reports 6: 27860. DOI: 10.1038/srep27860

2Zukoff, S. N. et al. 2016. Journal of Economic Entomology 109: 1387-1398. DOI: 10.1093/jee/tow073

3Dunbar, M. W. and Gassmann, A. J. 2013. Journal of Economic Entomology 106: 168-180. DOI: 10.1603/EC11291

EPA Public Comment Period Open on Neonicotinoid Insecticide Ecological Risk Assessments, Closes February 20

The EPA recently opened a public comment period on ecological risk assessments of four neonicotinoid insecticides as part of the ongoing registration review for these materials. The purpose of this comment period is to allow stakeholders and the general public to provide input on the risks and benefits of these materials related to their use in agricultural production. A press release detailing this announcement can be found at the following link: At the bottom of the page, links are provided to the registration review “dockets” where specific documents can be viewed and comments can be submitted. The active ingredients included under this review include (example trade names in parentheses) imidacloprid (Admire Pro®, Gaucho®), clothianidin (Poncho®, Belay®), thiamethoxam (Cruiser®, Endigo®), and dinotefuran (Certador®, Safari®).

The documents being released for comment can be found under the “Supporting Documents” heading within each individual docket, while the link to comment can be found on the main page for each docket. If you are interested in submitting a comment, I would encourage you to view “Tips for Effective Comments” at the following link: Information that could help to inform EPA’s regulatory process would include real-world usage rates, target pests, application methods, and observed benefits and/or risks to production systems from the use of these materials.

Calling Central Illinois Landowners with CP42


Agriculture comprises nearly half of terrestrial global landscapes posing a number of challenges to native pollinators. However, the Conservation Reserve Program’s CP42 Pollinator Habitat program aims to mitigate these challenges by providing pollen and nectar resources for pollinators where they may be lacking.

With funding from the National Institute of Food and Agriculture (NIFA) and the North Central IPM Center, Madeline Kangas, a University of Illinois graduate student in the Department of Natural Resources and Environmental Sciences, is starting a project to evaluate the capacity of CP42 Pollinator Habitat in Illinois’s agricultural landscapes to support different bee species. Her research study also aims to characterize the presence of agricultural pest species that may be utilizing the habitat alongside pollinators.

She is looking for CP42 sites that have been established for at least 2 full years by May of 2018 and are at least one acre in size. Participation in this study means that your CP42 site would be surveyed every 2-4 weeks from May through August in both 2018 and 2019. At the conclusion of the survey, each landowner will receive a comprehensive inventory of the plant, bee, and possible pest species on their site, and she hopes the knowledge gained will contribute to a greater understanding of which insects are using the space and how pollinator plantings can be improved in the future.

If you are interested in participating or would like additional information about this study, please contact Madeline Kangas by phone at (217) 722-4856 or email at A request for more information does not obligate you to participate in any study.

Thank you for considering this research opportunity.

Increased Insect Densities Reflected in Annual Corn and Soybean Survey


Thirty-six counties representing the nine crop reporting districts were surveyed at the end of July/beginning of August as part of our annual statewide corn and soybean survey. The surveys were performed by sampling five corn and five soybean fields per county. For the past several years (2011, 2013–2017), surveys in corn and soybean fields have been conducted with the goal of estimating densities of common insect pests. The estimates provided in this article should not be considered a substitute for scouting individual fields and making informed pest management decisions—even areas of the state that appear to be at low risk could have contained fields with high densities of a given insect pest.

Crop Reporting Districts

Figure 1. Illinois crop reporting districts surveyed during 2017 annual corn and soybean insect survey.


Western corn rootworm beetles were sampled in cornfields by counting the number of beetles on 20 consecutive plants beyond the end rows of a given field—a beetle per plant average was calculated for each field. A mild winter followed by favorable conditions at egg hatch and adult emergence helped the small populations from 2016 gain some traction in 2017 (Table 1). Per plant averages are up compared to recent years, though looking at the big picture, these numbers are still considered low. The district average from the northeast (1.95 beetles per plant), was affected by a single field in LaSalle county that average 7 beetles per plant which leads to a very important point to consider with this survey. Fields are randomly selected. We have no knowledge of insect management strategies that are used – soil insecticides, transgenics, or foliar applications.


Within an adjacent soybean field, 50 or 100 sweeps were performed on both the exterior of the field (outer 2 rows) and interior (at least 12 rows beyond the field edge) using a 38-cm diameter sweep net. The insects collected in sweep samples were identified and counted to provide an estimate of the number of insects per 100 sweeps (Tables 2 and 3).




The number of western corn rootworm adults in soybean fields throughout the state was low as well. The greatest number of beetles in soybeans occurred in McLean County, 8.00 beetles per 100 sweeps. All other counties sampled had fewer than 5 beetles per 100 sweeps (range of 0 to 2.4 per 100 sweeps).

Japanese beetles continued to increase in number from 2016 in the western part of Illinois. Both Fulton and McDonough counties recorded over 200 beetles per 100 sweeps in several fields, with their county averages of 525 and 340 beetles per 100 interior sweeps, respectively. Undoubtedly some of the highest numbers I’ve seen in this survey.

Overall, grape colaspis numbers were higher in several districts. This follows earlier reports during the growing season of grape colaspis feeding in soybeans. Unfortunately, there is no direct correlation between grape colaspis presence in soybeans and potential for larval injury in corn the following year. Numbers continue to be variable for this insect, but were high in the east southeast counties and should bear watching in 2018.

Stink bug injury in soybeans continues to make news in the southern states. We saw little damage caused by stink bugs in this survey, though numbers were slightly higher than past years. We continue to monitor for potential spread of not only the southern species like red banded and redshouldered stink bugs, but also the spread of brown marmorated stink bug as it gets its foothold here in Illinois.

Funding for survey activities was provided by the USDA National Institute of Food and Agriculture. This survey would not be possible without the hard work and contributions of many people. I would like to thank Illinois Cooperative Agriculture Pest Survey Program interns Evan Cropek, Ryan Pavolka, Emma Sementi, Jacob Styan and Hannah Hires as well as Department of Crop Science interns Lacie Butler, Kaela Miller, and Matt Mote.

Join us for the Ewing Agronomy Field Day on Thursday, July 27, 2017

The University of Illinois Extension will host the Ewing Demonstration Center Agronomy Field Day on Thursday, July 27, 2017 at 9 a.m.  Every growing season presents challenges to production, and this year is no exception!  We are happy to host this summer field day to share with local growers current, ongoing agronomy research in southern Illinois, including cover crop trials on corn and soybeans, nitrogen management in corn, weed management in soybean, and our continuous no-till field, now in its 49th year of continuous no-till production.


The topics to be discussed at Field Day include:


Managing Nitrogen for Corn & 2017 Growing Season Overview

  • Emerson Nafziger, Extension Crop Specialist, University of Illinois

Management Strategies for PPO-resistance

  • Karla Gage, Assistant Professor—Weed Science, Southern Illinois University

Southern Rust Management in Corn

  • Talon Becker, Extension Educator, University of Illinois

Insect Headlines in 2017

  • Kelly Estes, State Survey Coordinator, Illinois Cooperative Agriculture Pest Survey Program

Cover Crops:  The Good, The Bad, and The Practical

  • Nathan Johanning, Extension Educator, University of Illinois


The field day is free and open to anyone interested, and lunch will be provided.  Certified Crop Advisor CEUs will also be offered.  The Ewing Demonstration Center is about 20 minutes south of Mt. Vernon located at 16132 N. Ewing Rd; Ewing, IL 62836, on the north edge of the village of Ewing, north of the Ewing Grade School on north Ewing Road.  Watch for signs.  To help us provide adequate lunch and materials, please RSVP to the University of Illinois Extension Office in Franklin County at 618-439-3178 by Monday, July 24.  For additional information on the field day, contact Marc Lamczyk at the number above or