Source: OHIO STATE UNIVERSITY submitted to
INTEGRATING BEES INTO MODERN IPM: REVISING PEST MANAGEMENT APPROACHES IN A POLLINATOR-DEPENDENT CROP
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1029114
Grant No.
2020-67034-38066
Cumulative Award Amt.
$19,694.18
Proposal No.
2022-07126
Multistate No.
(N/A)
Project Start Date
Jul 1, 2022
Project End Date
Jun 30, 2024
Grant Year
2022
Program Code
[A7201]- AFRI Post Doctoral Fellowships
Project Director
Leach, A.
Recipient Organization
OHIO STATE UNIVERSITY
1680 MADISON AVENUE
WOOSTER,OH 44691
Performing Department
(N/A)
Non Technical Summary
The economics of agriculture often motivate growers to adopt certain practices. However, some of the economic outcome of pest management approaches are poorly described or understood. In the case of specialty crop production, growers often rely on insecticide applications for season-long pest control. While a wealth of research generally espouses the benefits of threshold-based insecticide programs, no study has compiled all findings together and provide evidence that threshold-based insecticide application programs are more effective and less costly over the conventional pest control approach. This project will be aimed at defining the benefits of this pest management approach as well as define drawbacks and further areas of need. Thus, supporting a long-term goal to produce effective and sustainable management recommendations that integrate pest management practices.
Animal Health Component
5%
Research Effort Categories
Basic
85%
Applied
5%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21114991130100%
Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants;

Subject Of Investigation
1499 - Vegetables, general/other;

Field Of Science
1130 - Entomology and acarology;
Goals / Objectives
In converting this fellowship to a standard grant, I will be continuing to work on objective 3, which will explore the utility of threshold-based insecticide programs to manage pests in pollinator dependent cropping systems.The loss of bee visitation and agronomic yield using insecticides with high bee toxicity will warrant higher pest economic thresholds.Rationale: Growers often choose the most inexpensive and effective insecticides to manage pests, however many of these insecticides are highly toxic to pollinators and can lead to a host of non-target effects on natural enemies. Additionally, these insecticides are unnecessary and threaten grower livelihoods as they increase the risk of insecticide resistance, increase input costs and potentially degrade ecosystem services. Further research is needed to quantify the economic effect of threshold-based insecticide programs on pollinators and agronomic yield. I predict that insecticide price alone is a poor measure of costs to growers since non-target effect on yield via changes in pollinator function are unaccounted for.Economic threshold review. While threshold-based insecticide programs have been developed for dozens of crops across the world, little has been done to quantify the impacts of these programs in specialty cropping systems. As a result, we have a limited understanding of how these programs could support critical ecosystem services like biological control and pollination. In pollinator-dependent crops, this is especially useful as we can potentially boost pollination services with only additional scouting. For the next year, I will delve further into the utility of threshold-based insecticide programs by reviewing current literature and providing a meta-analysis that will compare the use of this IPM tactic across specialty crop production, and especially in pollinator-dependent crops.
Project Methods
Economic threshold with pollinator considerations. Previous studies have examined the effect of insecticide product on economic thresholds (Nault and Shelton 2010), however no studies have applied this approach to pollinator toxicity. Conceivably, products with higher toxicities to bees should necessitate higher economic thresholds than products with low bee toxicity values. In this revised economic analysis, I will leverage data gained from objective 2 to revise economic thresholds for cucumber beetle management in watermelon. Ultimately, the benefit of pest management is contingent on the costs associated with the practice (Stern et al 1959; Pedigo et al 1986):Where EIL is the economic injury level, C= cost of insecticide ($/ha), D= damage caused per pest (kg/ha), I= density of pest, V= value of crop ($kg/ha), and K= proportion reduction in pest population by insecticide (%). While this approach defines the pest infestation level needed to justify an insecticide application, it does not account for the costs of the practice to the pollinator community and potential negative effects to agronomic yield. Therefore, I propose to analyze the cost (C) with an additional term similar to the environmental values proposed by Higley and Wintersteen (1992). In this formula, a new term will be added to the cost of the insecticide product, P, which will account for negative effects of the insecticide product on the pollinator community. This term will be defined by leveraging data from objective 2, specifically accounting for any yield loss (Y) associated with the insecticide treatments and reduced pollinator visitation (B):Yield losses (Y) will be determined by comparing all insecticide treatments to the untreated control. For example, Foster and Brust (1995) observed a 39% decrease in yield from insecticide applications, which the authors suggest may be due to decreased pollination. Mathematically, the reduction in yield would make the crop less valuable, thus necessitating a higher economic injury limit for the insecticide applications.Pollinator visitation is important to ensure fruit set, however previous research has shown that certain insecticides can significantly reduce visitation (Gillespie et al 2014; Gillespie et al 2015; Tschoeke et al 2019). Therefore, I will account for this reduction in visitation by comparing visitation rates between insecticide treatments and the untreated control. In combining these terms, I will include a pollination cost (P) to the aforementioned formula, which sums the effects of both Y and B:

Progress 07/01/22 to 06/30/24

Outputs
Target Audience:This project serves agricultural producers that struggle with arthropod pests, since this meta-analysis determined the impact of threshold-based management approaches on pest densities, pest damage, yield and beneficial insects (which includes pollinators). While results of this analysis will be applicable to all growers, we did not report any specific impacts to communities that are socially, economically or educationally disadvantaged. Furthermore, our results are also relevant to related agroecologist and applied entomologists who interact with agricultural pest management. Changes/Problems:The original context of this meta-analysis has changed since its inception. Prior to gathering data, we believed there would be a large number of manuscripts that we could mine for threshold-based impacts on pollinator activities (e.g., visitation, fruit set). However, after delving into the literature, we realized a relative dearth of studies (only 3 studies) which would not provide the statistical power for a meta-analysis. Thus, we broadened our search to determine the greater impact of threshold-based insecticide programming efforts on agricultural pest management. As a result, our meta-analysis has a larger impact on agriculture and provide deeper insights into the benefits of threshold-based insecticides program (e.g., less insecticide and higher beneficial insect numbers without compromising yield). While more replication is needed in the field, we do see promising results of threshold-based insecticide program boosting pollinator visitation in specialty cropping production. What opportunities for training and professional development has the project provided?As the lead PD to the project and primary author behind the work, this experience enabled me to delve further into meta-analysis and its associated statistical analysis which was a new skill for me. I also presented this work academically in a seminar. How have the results been disseminated to communities of interest?The work was communicated through in-person seminars or presentations (seminar provided to Michigan State University Entomology department, student talks were given at Ohio State University Entomology department and National Entomologicial society of America). A manuscript has also been submitted and we are awaiting reviews. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The major goal of this project was to complete objective 3 of a NIFA Postdoctoral fellowhip- the overall objective was to determine the utility of threshold-based insecticide programs to manage pests in pollinator dependent cropping systems through a meta-analysis that evaluted the impact of threshold programs on 1) pest densities, 2) beneficial insects and 3) crop yield parameters. Major Activities completed: Economic threshold review: A total of 126 manuscripts were mined for data regarding the efficacy of threshold-based insecticide programs in agriculture. In total, we collected data on the impact of threshold-based insecticide programs on, 1) pest densities, 2) pest damage, 3) yield and 4) beneficial arthropods. Data Collected A paper was considered eligible for the meta-analysis if 1) threshold-based insecticide programs were compared against either a calendar-based or weekly insecticide program and/or untreated control, 2) number of insecticide applications was reported, and 3) a metric of agricultural production was reported (e.g., yield, arthropod pest density or damage). Only studies that included a replicated design were included in the database (i.e., demonstration trials comparing two fields were excluded). The database included studies of agricultural crops used for food, fiber and/or feed, but excluded ornamental or landscaped systems. The data extracted from eligible papers included the total number of insecticide applications, the commodity of study, the insect pest(s), sample size (e.g., replicate number), and pesticide programming (regime and active ingredients). In addition, means and standard deviations for any of the following was also recorded: pest density, pest damage, insecticide cost, yield metrics, arthropod-mediated plant disease, beneficial insects. Yield metrics associated with crop yield and crop quality were recorded to parse out impacts of pest feeding. Crop yields were reported as harvested weight across unit area (e.g., tons/acre, bushels/ha) whereas crop quality metrics were specific to the system and appealed to established marketing standards (e.g., deformation of fruit, grain moisture). Often, crop quality was expressed as a proportion (% marketable from total yield) in relation to the marketing standard criteria. When a study measured data across multiple time points (e.g., pest counts from weekly surveys across a growing season), we averaged these data points to create one value with the aim of reducing inflation of the dataset. Variation associated with trials within a study was also recorded (e.g., cultivar, year, site). Beneficial insects were reported as a density (e.g., pollinators per flower per minute) or as a level of pest control (e.g., aphid mummies per plant). In cases where multiple thresholds were examined, the author-recommended threshold was classified as the 'threshold' treatment. Calendar-based insecticide programs were assumed to be those insecticide programs indicated as "standard practices" from the text or were sprayed weekly with insecticides. Summary statistics and discussion of results Pest Densities and Damage Estimates of pest populations were highest in untreated controls compared to calendar- (p<0.0001, n=63) and threshold-based insecticide (p<0.0001, n=71) programs. Calendar-based insecticide programs had the lowest pest densities and, on average, were significantly lower than threshold insecticide programs ( p=0.0019, n=68). Estimates of crop damage were similar; untreated control values were significantly higher than calendar-based (p<0.0001, n=60) and threshold insecticide programs (p<0.0001, n=64). However, calendar-based and threshold insect programs were statistically similar and had low levels of pest damage to the crop (p=0.9659, n=67). Beneficial Arthropods Threshold-based insecticide programs had improved beneficial arthropod outcomes compared to calendar-based insecticide programs (p= 0.0108, n=7). However, greatest values for beneficial arthropod health were reported in untreated controls, which did not receive insecticide. Both calendar (p<0.0001, n=7) and threshold-based insecticide programs (p=0.0028, n=7) had significantly lower beneficial arthropod values. Yield Outcomes Overall yield (weight of harvested crop per unit area) was statistically similar between threshold and calendar-based insecticide programs (p=0.748, n=90). However, untreated controls had significantly lower yields compared to threshold (p<0.0001, n=88) and calendar-based insecticide programs (p<0.0001, n=82). Yield quality metrics were significantly different between all treatment groups. Both threshold and standard insecticide programs had significantly higher yield quality metrics compared to untreated controls. However, calendar-based insecticide programs had a significantly higher level of quality compared to threshold insecticide programs (p=0.0407, n=30). Insecticide Applications and Cost Overall, the threshold-based insecticide program significantly reduced insecticide applications compared to calendar-based insecticide programs (p<0.0001). Approximately 91% of studies reported a decrease in insecticidal input with the use of a threshold, whereas the remaining 9% of studies reported either no change (2% studies) or an increase (4%). This reduction in insecticide resulted in a 39% decrease in insecticide cost in threshold-based insecticide programs (n= 36). Insecticide cost reductions ranged from 14% to 91%. Key outcomes or other accomplishments realized Thresholds reduced insecticide applications by 44% without significantly compromising pest control or yield compared to calendar programs. Insecticide cost was also reduced, by 40%, in the threshold treatment, while decreasing off-target impacts (e.g., beneficial insect abundance) and providing similar levels of disease control. Given the extent and consistency of these benefits, greater policy and financial support are needed to encourage this practice in agriculture. Further, we reported evidence that pollinators would be benefitted through threshold-based insecticide programs, which offers a greater advantage to pollinator-dependent crops.

Publications

  • Type: Journal Articles Status: Submitted Year Published: 2024 Citation: Leach, A., Gomez, A., and I. Kaplan. Threshold-based management reduces insecticide use by 44% without compromising pest control or crop yield. In review at Sustainable Agriculture


Progress 07/01/22 to 06/30/23

Outputs
Target Audience:Currently, the target audience has been primarily aimed at stakeholders and fellow researchers who work in pest management. This includes those individuals within my immediate region (e.g., Midwestern Growers) as well as those at larger scales (e.g., national commodity groups). This audience was reached through research and extension presentations. I have also produced graphics that illustrate key findings which have been shared with stakeholder groups. Research efforts were also reported to an academic audience (faculty, students, postdoctoral researchers, etc.) through invited departmental seminar series. Changes/Problems:I had to extend the life of the grant by a year to finish the statistical analysis. Due to the independent consultation required for the analysis, we were not able to finish the grant within the range originally proposed. This delay has not significantly slowed the process and we still anticipate final submission of the manuscript and project within the next 2-3 months. What opportunities for training and professional development has the project provided?I have had many opportunities for training and professional development. This project has challenged my skill set and improved my scientific communication. I have had the chance to speak about this research in professional avenues (2 presentations 2023), and mentored a graduate student to give a presentation on the topic (an additional 2 presentations 2022-2023). In addition, I have 1 publication that I am submitting to a higher impact journal (goal = IF>6). In terms of technical skills, I've gained knowledge of statistical code for meta analysis which was used in this study. How have the results been disseminated to communities of interest?The research has been reported in 4 different presentations over the past 4 years (as indicated above). However the formal dissemination of this research will come from the final publication, which is in the final stages now and will be submitted within the next month. What do you plan to do during the next reporting period to accomplish the goals?I will continue to write up the publication, review the manuscript and submit the manuscript for publication in a peer-reviewed journal.

Impacts
What was accomplished under these goals? These goals are nearly accomplished. I have created a team to help me pursue the literature (Purdue University + Ohio State University) to identify the publications ideal for this study. In total, we have collected 126 studies which represent >400 trials that test the impact of threshold in agricultural pest management. Analysis was conducted in Summer 2023 by an independent consultant. We now have the results and are finishing the manuscript.

Publications

  • Type: Journal Articles Status: Accepted Year Published: 2022 Citation: Leach, A. and Kaplan, I. 2022. Prioritizing pollinators over pests: wild bees are more important than beetle damage for watermelon yield. Proc. R. Soc. B.2892022127920221279. https://doi.org/10.1098/rspb.2022.1279
  • Type: Journal Articles Status: Accepted Year Published: 2022 Citation: Leach, A., Pecenka, J., and Kaplan, I. 2022. Does IPPM bear fruit? Evaluating reduced?risk insecticide programmes on pests, pollinators and marketable yield. J. App. Eco., 1365-2664.14294. https://doi.org/10.1111/1365-2664.14294
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2023 Citation: Leach, A. and I. Kaplan. 2023. Minding your bees: Impacts of integrated pest and pollinator management in cucurbits. National Entomological Society of America. National Harbor, MD. November 5-8.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2023 Citation: Leach, A. and I. Kaplan. 2023. Putting the 'pollinator' in IPM: a case study from cucurbits. International Conference on Pollinator Biology, Health and Policy. June 6, 2023. State College, PA.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2023 Citation: Leach, A. and I. Kaplan. 2022. Implementing cucumber beetle IPM for pollinator protection. IPM symposium, March 1. Denver, CO.