ECOLOGY AND MANAGEMENT OF ARTHROPODS IN CORN

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1013912
• Project No.: WIS01994
• Multistate No.: NC-_old246
• Project Start Date: Oct 1, 2017
• Project End Date: Sep 30, 2020

Project Director
MITCHELL, PA, D.

Recipient Organization
UNIV OF WISCONSIN
21 N PARK ST STE 6401
MADISON,WI 53715-1218

Performing Department
Agri and Applied Economics

Non Technical Summary
Over the last decade, insect management in corn has become dominated by seed-based technologies such as Bt corn and neonicotinoid seed treatments. Hence, farmers make major insect management decisions when purchasing seed, several months before planting and pest activity. Scouting-based integrated pest management (IPM) is no longer relevant for "modern" corn as cropping systems for many pests. As a result, insect management takes on aspects of risk management, akin to insurance decisions, which is conceptually quite different from scouting and making foliar insecticide application decisions within a few days. Based on this context, this project focuses on improving insect management for corn by updating economic analysis methods and IPM management recommendations for the use of seed-based insect management technologies in a risk management context.Project objectives begin by assembling existing data from small plot studies around the Midwest, focusing on corn rootworm and lepidopteran pests of corn. Using these data, probability density functions for baseline pest pressure, the efficacy of different control options, and yield impacts will be estimated. Next, these density functions will be integrated into an empirical model and Monte Carlo simulation used to generate risk-based measures of the value of each control option, including measures such as the average net return and its variability, as well as the breakeven probability. Results will be publicized through in-state Extension channels and regionally via the NC246 regional committee, plus multiple peer-reviewed journal submissions are anticipated.

Animal Health Component

0%

Research Effort Categories

Basic

10%

Applied

40%

Developmental

50%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
211	1510	3010	60%
211	3110	3100	40%

Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants;

Subject Of Investigation
1510 - Corn; 3110 - Insects;

Field Of Science
3010 - Economics; 3100 - Management;

Keywords

corn rootworm

corn borer

integrated pest management

ipm

economics

bt corn

neonicotinoid

Goals / Objectives
<b> Investigate the relationship between pest management technologies and the agricultural environment.</b> <p> 1a. Assess the need, efficacy and pest management window of seed treatment insecticides, primarily neonicotinoids, to control secondary below-ground insect pests.<p> 1b. Evaluate possible effects of insecticidal seed coatings on non-target beneficial insects. <b>Develop and assess IPM and IRM systems for the arthropod complex in corn.</b> <p> 3a. Characterize and monitor for resistance of lepidopteran pests to Bt corn and conventional insecticides, and assess possible IRM and mitigation strategies.<p> 3b. Characterize geographic extent and nature of resistance of <i>Diabrotica</i> spp. to Cry toxins, pyrethroids, and other insecticides, and develop appropriate IPM and IRM strategies for problem areas.<p> 3c. Work toward improving an artificial diet for WCR rearing and more sensitive bioassays of toxins.<p> 3d. Develop strategies to manage the ear-feeding pest complex and model implications for IRM and IPM.<p> 3e. Develop <i>Helicoverpa armigera</i> early detection and mitigation network.<p> 3f. Develop region-specific bioeconomic models to assess refuge and IPM strategies for managing lepidopteran and coleopteran pest resistance to Bt corn expressing stacked and pyramided toxins.<p> 3g. Assess the extent to which limited farmer access to Bt corn varieties targeting only coleopteran or only lepidopteran pests affects the risk of resistance when the economic importance of each pest varies regionally. <b>Employ diverse delivery methods to disseminate information related to sustainable management of corn arthropod pests.</b> <p> 4a. Establish an NC-205 video library website with permanent high quality versions of IPM videos for open online access and download to computer and portable electronic devices.<p> 4b. Produce and deploy a comprehensive IPM system for cost-effective prevention, early detection, rapid diagnosis, and mitigation of new and emerging corn pests that links all stakeholders who have common interests in pest detection and management.<p> 4c. Develop an array of IPM and IRM distance education workshops.

Project Methods
This project has four objectives: 1) Assemble small plot data, 2) Estimate stochastic relationships, 3) Conduct Monte Carlo analysis to develop risk-based IPM recommendations, and 4) Publicize results.Assemble small plot data: This project will assemble existing data from field studies similar to a meta-analysis, focusing on major corn pests. Many of these studies are routine efficacy experiments, useful for outreach purposes and generating regulatory data, but often difficult to publish in peer-reviewed academic journals, through scientifically valid. As a result, the Entomological Society of America publishes Arthropod Management Tests (AMT), an editor-reviewed publication that contains reports of experiments considered to be routine and potentially not suitable for publication in other scientific journals. Journal publications and extension and departmental publications of various sorts exist that will be used. In addition, personal connection with members of the NC246 committee will help in identifying additional data.Most of the data exist as pdf documents and so the data will have to be entered by hand into a database. The initial focus will be on key insect pests of corn such as corn rootworm (Diabrotica spp.) and European corn borer (Ostrinia nubilalis), and then move to currnlty minor pests such as black cutworm (Agrotis ipsilon), fall armyworm (Spodoptera frugiperda) and corn earworm (Helicoverpa zea).To be included, data must be from randomized and replicated field studies that include at least two treatments - a baseline (often an untreated control) and treatments commonly used by farmers, such as Bt seed, an insecticide seed treatment, a soil applied insecticide, or a foliar applied insecticide. In order to estimate the statistical distributions for parameterizing the conceptual model, data for pest pressure and/or yield must be reported for each treatment. For example, data on pest pressure for an untreated control and each insecticide treatment could be pooled with data from other studies to estimate control efficacy distributions for an insecticide treatment. In terms of pest pressure, the focus will be on studies that report node injury scale (NIS) for corn rootworm, and per plant larval tunneling and/or larval populations for European corn borer or other Lepidopteran pests.Estimate stochastic relationships: This objective will use the assembled small plot data to estimate three probability density functions to empirically parameterize the conceptual model, focusing initially on corn rootworm in corn. First is the statistical distribution of the untreated NIS for rootworm for the baseline pest pressure (NIS0). Because the NIS ranges from 0 to 3, the beta density is a good candidate, as it has set lower and upper limits and is flexible, able to capture skewness in either direction, and easily estimated via maximum likelihood. Second are the statistical distributions of the pest pressure remaining after use of each control method. For the NIS, again a beta density will be used to have a consistent pest pressure model, but estimated parameters will depend on the initial pest pressure NIS0 to capture the connection with the initial pest pressure. These estimated conditional probability densities will describe the stochastic nature of the efficacy of pest control, creating a stochastic model of control efficacy for the different management technologies. Third is the statistical distribution of crop yields after use of each control method. For corn yield, the PI has estimated this yield relationship previously for tunneling by lepidopteran larvae and the NIS. This project will replicate these methods using the larger data set assembled.Conduct Monte Carlo analysis to develop risk-based IPM recommendations: These estimated density functions fully parametrize the conceptual model for a pest-crop system once combined with USDA crop yield and price data and pest control cost information. Because analytically determining the distribution of final profit for each control technology is analytically intractable given the linked conditional distributions for pest pressure, control efficacy and yield impacts, Monte Carlo simulation will be used. For example, this would first require several thousand draws of NIS0 from a beta density. Then for each random draw, one would calculate the parameters for the NIS with treatment and draw those. Then for each pair of NIS0 and NIS with treatment, the yield loss would be drawn based on the updated distribution. Finally, profit would be calculated based on a randomly drawn pest-free yield, and assumed (non-random) corn price and technology cost. The final outcome would be several thousand random draws of farmer profit. If done correctly, these Monte Carlo draws can be used to calculate the expected net value of pest control and breakeven probabilities by using the sample counterparts. For example, the sample average of the thousands of random draws is the Monte Carlo estimate of the expected value.Once the Monte Carlo simulations have been implemented, risk-based IPM recommendations will be developed. One measure of value for a control practice is the increase in expected profit. As a hypothetical example, suppose the Monte Carlo estimated expected profit is $120/A without corn rootworm control and $140/A with rootworm Bt corn, so that the average value rootworm Bt corn is $20/A. However, because this value is also random, the breakeven probability is another measure that indicates the riskiness of the practice. The final outcome in this hypothetical case might then be a statement as follows: "With an average yield of 200 bu/A, a corn price of $3.00/bu, and a cost of $30/A for rootworm Bt seed, the average net gain is $20/A with a break even probability of 65%." Comparable statements could be generated for different yield, price and cost assumptions and for different control options (soil applied insecticide, neonicotinoid seed treatment). By reporting the average gain and a measure of its risk, farmers can decide how they want to tradeoff gain and risk. For example, suppose that the comparable results for a soil insecticide was an average net gain of $10/A and a breakeven probity of 95%. Some farmers would choose the $20/A average gain with a 35% chance of actually losing money, while others would be more risk averse and choose the smaller average gain with only a 5% chance of losing money.Publicize results: This project is quite applied, focusing on key crops, and so the outreach interest will be high both in Wisconsin and regionally. Furthermore, the proposed process for generating risk-based IPM recommendations should be a sufficient research contribution to warrant publication, at least some project components. The PI has an active outreach program in Wisconsin and will use it to publicize results at venues such as the Corn-Soy Expo and the Wisconsin Crop Management Conference, where he presents regularly. He is also co-director of UW Extension&#39;s Nutrient and Pest Management Program and will use that venue to create and publicize outreach materials, such as the IPM Toolkit, an app for mobile devices (http://ipcm.wisc.edu/apps/). Finally, he is an active participant in NC246, which also has outreach objectives (http://tinyurl.com/z74gmgo), and so he will work with members to develop and publicize results.

Progress 10/01/17 to 09/30/20

Outputs
Target Audience:The target audience includes corn growers, agricultural professionals (e.g., crop consultants, ag chemical sellers), graduate students, and research and outreach faculty and staff in NC246 and allied groups. This audience is being reached using both written and verbal outreach methods through extension channels, at research meetings of NC246 and at national and regional academic conferences, as well as via student mentoring of graduate research and in the undergraduate classroom. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project facilitated a PhD graduate students&#39; opportunity to write a research manuscript for submission as a peer-reviewed publication (Saikai et al. 2020). He completed his PhD and graduated in May 2020 and has taken a position on the faculty at the University of Melbourne in Australia in the Maths Stats department. How have the results been disseminated to communities of interest?The primary mechanism has been as journal articles (Hurley and Mitchell 2020; Saikai et al. 2020) and a poster at an academic conference (Hanson et al. 2019). In addition, a blog post "Gene drives in Wisconsin agriculture: What are they and should you support it?" was written for a lay audience for the Jones et al. (2019) paper from the previous reporting period: https://renk.aae.wisc.edu/2019/10/02/gene-drives-in-wisconsin-agriculture-what-are-they-and-should-you-support-it/. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Specific to NCR246 goals, two manuscripts were published in Pest Management Science (Hurley and Mitchell 2020; Saikai et al. 2020). In addition, a co-author presented an updated version of our older work (Hutchison et al. 2010) as a poster at a conference (Hanson et al. 2019). These materials all contributed to goal 2 of the project "Develop and assess IPM and IRM systems for the arthropod complex in corn." Seed?based technologies (Bt seed, seed treatments) dominated insecticide use. Almost 80% of respondents&#39; planted hectares used Bt crops and more than half used seed treatments, while about one?sixth used soil insecticides and one?sixth to one?third used foliar insecticides. Perceived farmer values per treated hectare were greatest for Bt cotton and foliar insecticides in cotton, especially after first bloom. Values for maize and other cotton insecticide uses were greater than for soybean. Aggregating over treated areas, the largest total values for each crop were for seed?based technologies. In addition to yield and cost, farmers showed significant concern for economic risk and human and environmental safety when making pest management decisions. These non?monetary concerns significantly affected the likelihood farmers used these practices and their perceived value. When farmers use risk-based IPM, an insecticide can be justified based on an ex ante assessment, but ex post, after the uncertainty is resolved, it can be the case that the insecticide was not needed. Hence, ex post evaluations of the estimated average return from using an insecticide will be lower than when using an ex ante assessment. Furthermore, risk-based IPM has a subjective element. Two farmers facing the same decision scenarios may choose different pest management practices due to differences in their willingness to bear risk or their preferences regarding human and environmental safety. Appropriate use of seed-based insecticides in IPM is a vexing but nuanced problem, with many stakeholders expressing different views of how to pursue economic and environmental outcomes that are often similar. The debate commonly focuses on the appropriateness of prophylactic insecticide use as a type ofinsurance in risk-based IPM or whether seed-based technologies are comparable with host plant resistance. Regardless of the ongoing debate, this is the timing of the actual pest management decisions most US cotton, maize and soybean farmers currently face and these results show that risk management, and human and environmental safety are significant considerations when they make these choices.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Saikai, Y, T.M. Hurley, and P.D. Mitchell. 2020. An agent?based model of insect resistance management and mitigation for Bt maize: A social science perspective. Pest Management Science https://doi.org/10.1002/ps.6016.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Hurley, T.M., and P.D. Mitchell. 2020. The Value of Insect Management to U.S. Maize, Soybean and Cotton Farmers. Pest Management Science https://doi.org/10.1002/ps.5974
• Type: Other Status: Published Year Published: 2019 Citation: Hanson, A., B. Potter, E.C. Burkness, R.D. Moon, K. Hamilton, P.D. Mitchell, A. Peltier and W.D. Hutchison. 2019. Areawide suppression of European corn borer after 23 years in Minnesota and Wisconsin: The benefits continue. Annual Meetings of the Entomological Society of America, St. Louis, MO, Nov 20, 2019.

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:The target audience includes corn growers, agricultural professionals (e.g., crop consultants, ag chemical sellers), graduate students, and research and outreach faculty and staff in NC246 and allied groups. This audience is being reached using both written and verbal outreach methods through extension channels, at research meetings of NC246 and at national and regional academic conferences, as well as via student mentoring of graduate research and in the undergraduate classroom. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project facilitated a PhD graduate student opportunity to attend a national academic conference to present research related to the project (Saikai, Y., and P.D. Mitchell. An agent-based model of insect resistance management and mitigation for Bt maize: A social science perspective. A poster was presented at the American Agricultural Economics Association Annual Meeting, Atlanta, GA, July 21-23, 2019). The project facilitated a PhD graduate student opportunity to write a research manuscript for submission as a peer-reviewed publication. How have the results been disseminated to communities of interest?-Project research output was presented at academic conferences (Saikai, Y., and P.D. Mitchell. An agent-based model of insect resistance management and mitigation for Bt maize: A social science perspective). -Poster at American Agricultural Economics Association Annual Meeting, Atlanta, GA, July 21-23, 2019 and Hutchison, W.D., E.C. Burkness, R.D. Moon, P. Mitchell, K. Hamilton, B. Potter, G. Dively. 2019. Success with Bt maize for European corn borer in the U.S.: Benefits of areawide pest suppression in maize and surrounding non-Bt crops. -27th International Working Group on Ostrinia (IWGO) &amp; International Organization of Biological Control (IOBC), Engelberg, Switzerland, Oct 14, 2019) with a new journal article published (Jones, M.S., J.A. Delborne, J. Elsensohn, P.D. Mitchell, and Z.S. Brown. 2019. Does the US public support using gene drives in agriculture? And what do they want to know? Science Advances 5(9):eaau8462 DOI: 10.1126/sciadv.aau8462) and another in preparation for submission. What do you plan to do during the next reporting period to accomplish the goals?Work in the next reporting period will focus on submitting a manuscript to Pest Management Science (An agent-based model of Bt corn adoption and insect resistance management).

Impacts
What was accomplished under these goals? Specific to NCR246 goals, manuscript "An agent-based model of Bt corn adoption and insect resistance management" was desk rejected at PLoS Computational Biology for not having enough biology. We have been re-writing the manuscript for submission to Pest Management Science. A version of this paper was presented as a poster at the Agricultural and Applied Economics Association annual meeting (Saikai, Y., and P.D. Mitchell). An agent-based model of insect resistance management and mitigation for Bt maize: A social science perspective. Poster at American Agricultural Economics Association Annual Meeting, Atlanta, GA, July 21-23, 2019). In addition, a co-author presented an updated version of our older work (Hutchison et al. 2010) at a conference (Hutchison, W.D., E.C. Burkness, R.D. Moon, P. Mitchell, K. Hamilton, B. Potter, G. Dively. 2019. Success with Bt maize for European corn borer in the U.S.: Benefits of areawide pest suppression in maize and surrounding non-Bt crops. 27th International Working Group on Ostrinia (IWGO) &amp; International Organization of Biological Control (IOBC), Engelberg, Switzerland, Oct 14, 2019). Our last report mentioned the Sporebuster smartphone app. The app can help determine a profitable program by entering your expected soybean price, expected yield, and treatment cost.Sporebusterinstantly compares ten different treatment plans at once to determine average net gain and breakeven probability of each. You can mark, save and share by email, the best plans for your farming operation. The tool has been shared with the public.

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Jones, M.S., J.A. Delborne, J. Elsensohn, P.D. Mitchell, and Z.S. Brown. 2019. Does the US public support using gene drives in agriculture? And what do they want to know? Science Advances 5(9):eaau8462 DOI: 10.1126/sciadv.aau8462
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Saikai, Y., and P.D. Mitchell. An agent-based model of insect resistance management and mitigation for Bt maize: A social science perspective. Poster at American Agricultural Economics Association Annual Meeting, Atlanta, GA, July 21-23, 2019.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Hutchison, W.D., E.C. Burkness, R.D. Moon, P. Mitchell, K. Hamilton, B. Potter, G. Dively. 2019. Success with Bt maize for European corn borer in the U.S.: Benefits of areawide pest suppression in maize and surrounding non-Bt crops. 27th International Working Group on Ostrinia (IWGO) & International Organization of Biological Control (IOBC), Engelberg, Switzerland, Oct 14, 2019.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:The target audience includes corn growers, agricultural professionals (e.g., crop consultants, ag chemical sellers), graduate students, and research and outreach faculty and staff in NC246 and allied groups. This audience is being reached using both written and verbal outreach methods through extension channels, at research meetings of NC246 and at national and regional academic conferences, as well as via student mentoring of graduate research and in the undergraduate classroom. Changes/Problems:As a pressing need arose, the models developed for insect management in corn for the project were adapted to the essentially similar situation of white mold in soybeans, resulting in a journal publication and a new smartphone app. What opportunities for training and professional development has the project provided?The project allowed the lead PI to attend and Present at the IPM for Early Season Pests Workshop held at Iowa State University in Ames, IA, June 19-21, 2018. Attendees included both academics, as well as farmers and crop consultants from Iowa. Also, the project facilitated a PhD graduate student&#39; opportunity to attend a national academic conference to present research related to the project (Saikai, Y., P.D. Mitchell, and J. Colquhoun. 2018. Multi-armed bandit for experimental plot selection. Select Paper, American Agricultural Economics Association Annual Meeting, Washington, DC, August 5-7, 2018). How have the results been disseminated to communities of interest?At the IPM for Early Season Pests Workshop held at Iowa State University in Ames, IA, June 19-21, 2018, attended by academics, farmers and crop consultants from Iowa, and at academic conferences (American Agricultural Economics Association Annual Meeting, XLI Biological Control National Congress). A smartphone app and training video were developed and disseminated via the iTunes and GooglePlay stores and YouTube. Also, two book chapters are available as open source research on the internet (Chavas and Mitchell 2018, Dong and Mitchell 2018). An academic journal article will also become available (Willbur et al. 2019). What do you plan to do during the next reporting period to accomplish the goals?Work in the next reporting period will focus on submitting a manuscript to PLoS Comp Bio (An agent-based model of Bt corn adoption and insect resistance management). In addition, the new smartphone app will be mentioned at Extension and pesticide applicator training meetings and similarly to spread awareness and increase use.

Impacts
What was accomplished under these goals? Research focused on adapting previously developed insect models to pathogen management in soybeans, as the need was pressing. The structure of the model was the same as for rootworm or corn borer in corn, but was white mold in soybean. For example, instead of a node injury scale for rootworm feeding damage on corn roots it was the disease severity index for white mold in soybean. This work led to a journal paper (Willbur et al. forthcoming) and a new smartphone app (sporebuster). This app will be used for the 2019 cropping season. Specific to NCR246 goals, research focused on preparing the paper "An agent-based model of Bt corn adoption and insect resistance management" for submission to PLoS Computational Biology. We anticipate submission in the next reporting period. In addition, a co-author presented an updated version of our older work (Hutchison et al. 2010) at a conference in Mexico (Hutchison, W.D., E.C. Burkness, and P.D. Mitchell. 2018. Area wide suppression of European corn borer via Bt maize in the Midwest U.S.: The benefits continue, 1997-2017. XLI Biological Control National Congress, Puerto Vallarta, Mexico Nov 8-11, 2018). Also, a presentation was made at a workshop in risk base-IPM (Economic Logic of Risk-Based IPM. IPM for Early Season Pests Workshop, Iowa State University, Ames, IA, June 19-21, 2018). Attendees included both academics, as well as farmers and crop consultants from Iowa.

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: Mitchell, P.D. Z. Brown, and N. McRoberts. 2017. Economic issues to consider for gene drives. Journal of Responsible Innovation https://doi.org/10.1080/23299460.2017.1407914.
• Type: Book Chapters Status: Awaiting Publication Year Published: 2018 Citation: Chavas, J.P., and P.D. Mitchell. 2018. Corn Productivity: The Role of Management and Biotechnology. Corn, InTech Publishing.
• Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Pyrethroid Use and Benefits to U.S. Agriculture. North Carolina State University and 2017 Workshop on Innovation and Regulation in Agriculture. Raleigh, NC, Oct 23-24, 2017.
• Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Parametrizing Bioeconomic Models of Soybean Pest/Pathogen Management with Small Plot Data (with N. Carey, J. Wilbur, D. Smith). ASA/CSSA/SSSA International Meetings, Tampa, FL, Oct 22-25, 2017.
• Type: Other Status: Published Year Published: 2017 Citation: Saikai, Y., and P.D. Mitchell. Agent-based model of Bt corn adoption and insect resistance management. Poster at American Agricultural Economics Association Annual Meeting, Chicago, IL, July 30-Aug 1, 2017.
• Type: Book Chapters Status: Published Year Published: 2018 Citation: Dong, F., and P.D. Mitchell. 2018. Welfare Analysis of the Prohibition of 2,4-D in the United States. Benefits and Economic Assessment of 2,4-D and the Phenoxy Herbicides in the U.S. Washington, DC: Industry Task Force II on 2,4-D Research Data. Online: https://24d.org/PDF/Newsroom-PDF/2_Welfare_Analysis_of_Prohibition_of_24-D_03-10-2018.pdf
• Type: Journal Articles Status: Accepted Year Published: 2019 Citation: Willbur, J.F., P.D. Mitchell, M. Fall, A. Byrne, S. Chapman5, C. Floyd, C. Bradley, K. Ames, M. Chilvers, N. Kleczewski, D. Malvick, B. Mueller, D. Mueller, M. Kabbage, S. Conley, and D.L. Smith. 2019. Meta-analytic and economic approaches for evaluation of pesticide impact on Sclerotinia stem rot control and soybean yield in the North Central U.S. Phytopathology forthcoming.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Saikai, Y., P.D. Mitchell, and J. Colquhoun. 2018. Multi-armed bandit for experimental plot selection. Select Paper, American Agricultural Economics Association Annual Meeting, Washington, DC, August 5-7, 2018.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Hutchison, W.D., E.C. Burkness, and P.D. Mitchell. 2018. Areawide suppression of European corn borer via Bt maize in the Midwest U.S.: The benefits continue, 1997-2017. XLI Biological Control National Congress, Puerto Vallarta, Mexico Nov 8-11, 2018.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Economic Logic of Risk-Based IPM. IPM for Early Season Pests Workshop, Iowa State University, Ames, IA, June 19-21, 2018.