This project will summarize a key set of published studies that demonstrate insects, especially pollinators can be conserved within and adjacent to crop fields (include soybean) using insecticides. This information can assist key stakeholders address the need to conserve endangered species that occur in regions where soybean production is common.
Pollinators, like the Rusty Patch Bumble bee, are found in Iowa and have been listed as endangered by the US Fish and Wildlife Service. The Environmental Protection Agency’s (EPA) response to the endangered species act (ESA) may affect soybean farmers who use insecticides and are trying to practice conservation in and around their fields. Iowa leads the nation in employing conservation practices that can benefit pollinators, including those supported by the USDA’s conservation reserve program. For example, Iowa has more acres in CP42 (pollinator habitat) than any other state. Iowa is also the birthplace of the prairie strip practice (CP43), which can increase the diversity and abundance of pollinators, especially bees. These are voluntary practices that farmers must choose to do. If restrictions are placed on insecticide use because of the proximity of these practices to crop fields, farmers may elect to stop participating in CP42, CP43 and other practices that could conserve pollinators. How we proceed in practicing agriculture and conserving species requires empirical evidence from Iowa, if Iowans are to contribute significantly to this issue.

During the 8-month period, a team of researchers will compile work conducted in Iowa and the surrounding Midwestern states, that can inform if and to what extent conservation and insecticide use can co-occur on the same farm.
Research conducted in Iowa has shown that CP43 can conserve pollinators even when the adjacent soybean or corn field is using insecticides. This work has been compiled in several articles in the last 5 years. Similar work has been done in other states for CP42 and other conservation practices.
We will compile these studies and summarize them considering the initial proposals by the EPA to respond to the demands of the ESA. This includes a discussion “PULAs” (pesticide use limitation areas) and “pick lists” that may allow farmers to consider conservation practices when selecting and using pesticides.
We anticipate at least one article for a peer-reviewed journal that targets an audience interested in conservation and agriculture. A similar article has been written by colleagues on the topic of Monarch butterfly conservation and published in the journal Bioscience (Grant et al. 2022). We will use this as a model for constructing a summary of this broader topic.
In addition, our project team will create a 3-4 page handout that summarizes the key findings of this review. This will include a summary of the main issue (how the EPA is responding to its responsibilities to the Endangered Species Act) with key terms defined, like what it means for a species to be listed as endangered and what constitutes ‘critical habitat’ under the ESA. This document will be shared with extension personnel in both Iowa and Illinois and made public through the Extension Store at ISU.

The main article will be written and submitted for review by October 2024. We anticipate a 1-2 month review period, We have made progress on researching this article and beginning plans for its completion.

Updated June 25, 2024:
At this stage, we have started to accumulate references and identify what will go into our manuscript. We have a very strong draft based on our previous experience in the field and are making plans now to better frame it to fit the goals of this project.

Updated October 28, 2024:
We have started assembling the manuscript described in the proposal, with the research team meeting biweekly to move the project forward. In addition to assembling the published scientific research, we have also sought information from regulatory literature, including the student supported on this work directly interfacing with regulatory agencies to better understand the future of pesticide regulation and relate it to the published scientific literature.

Updated July 30, 2025:
At the time of this report, we have submitted two manuscript to a scientific journal for publication. These are both under review right now.

Both of these articles are in review at a scientific journal. The first article is an exhaustive review of Prairie STRIPS and how conservation within conventional agriculture can still provide substantial benefits. The second article, while still peer-reviewed, is targeted to a general audience, and more explicitly addresses how new regulations could negatively impact how farmers implement voluntary conservation practices. The titles and current abstracts of these articles are listed below:

Title: "Can native vegetation in agroecosystems provide a net benefit for pollinators, despite pesticide use?"
Abstract: Pollinator health and population declines are of global concern, with
ramifications for biodiversity conservation and the human food supply.
While causes are multifold, habitat enhancement through the
establishment of native flowering vegetation is a broadly supported
conservation strategy. However, concerns about enhancing habitat in
agroecosystems with widespread pesticide use remain. We synthesize
research findings from a model conservation practice, prairie strips—
narrow patches of diverse, native plants within row crop fields —to
evaluate this tradeoff. Prairie strips enhance pollinator forage quantity
and quality, support a more diverse and abundant wild bee community,
and sustain North American monarch butterflies, while also increasing the
productivity of managed honey bee hives. Although exposure to
pesticides does occur, environmental concentrations are typically well
below levels that would have negative impacts on pollinator health. We
conclude a net positive effect of habitat enhancement and discuss these
findings within the broader context of pollinator conservation.


Title: "Insecticide regulations need to consider impacts on conservation adoption"
Abstract: The US Environmental Protection Agency recently implemented a new Insecticide Strategy. An updated strategy was urgently needed, given the increasing number of insects added to or proposed for listing under the Endangered Species Act, and the scientific evidence linking pesticides with precipitous declines in pollinators. Protecting non-pest insects requires “all hands-on deck”; however, the new strategy threatens to undermine support from a target group – farmers who use pesticides – crucial partners for achieving conservation goals. Imperatively, the strategy’s ambiguous language needs clarification. Care should also be taken to align the Insect Strategy with the USDA Conservation Reserve Program (CRP), a popular program that provides crucial financial support for farmland owners to voluntarily engage in conservation, including insect conservation. We spotlight the CRP prairie strip practice (CP-43) to exemplify problems with the new Insecticide Strategy. We also make recommendations to improve the policy for both farmers and the environment.

This project did not produce any scientific results, but we produced two manuscripts related to pesticide use and conservation in the corn/soybean agricultural systems of the Midwest, as described above.

Will inform practices related to pollinator and endangered species protection and regulation.