Soybean production continues to increase to meet world demand.  In 2021, the U.S. produced 4.44 billion bushels of soybeans, making it the second-largest soybean producer in the world (USDA, NASS 2022).  This represents a record value of $45.7 billion for U.S. soybean (USDA, NASS 2022).  Emerging and existing invertebrate pests continue to threaten soybean yield and quality as they adapt to management practices and expand their ranges.  In the short term, the loss of previously effective management tactics is increasing producer costs.  In the long-term, the establishment of invasive insect pests will continue to impact soybean ecosystems, altering integrated pest management (IPM) strategies that have proven effective in the past.  In the Midsouth and Southeast, corn earworm, soybean looper, and stink bugs such as the redbanded stink bug, brown stink bug, southern green stink bug, and green stink bug continue to be major pest issues.  In addition, the brown marmorated stink bug continues to expand its range (Koch et al. 2017), along with the southern green stink bug.  In 2020, the stink bug complex was the costliest pest group in soybean, followed by the corn earworm (Musser et al. 2021).  In the Mid-Atlantic, slugs are significant threats to soybean, particularly as soil conservation practices increase.  In the Midwest, the discovery of soybean gall midge (Gagne et al. 2019) as a new species and its establishment as a pest has the potential to irreversibly change soybean production (McMechan et al. 2021).  Existing pests such as the soybean aphid, Dectes stem borer, stink bugs, and a complex of insect defoliators have the potential to result in unacceptable yield loss when significant pressure occurs.  To address these concerns, a coordinated research and extension delivery project is necessary to understand pest biology, develop best management practices, and deliver recommendations to soybean producers.

Rapidly addressing stakeholder needs is the foundation of S1080.  Participants of S1080 maintain this exceptional track record of response through state, regional, and national soybean commodity groups as well as partnerships with industry and non-governmental organizations.  The regional response as a result of S1080 has allowed for the development of effective soybean insect IPM research projects and the dissemination of research-based information through extension activities.  This approach has the additional benefit of avoiding overlapping research among regions while maximizing collaborations.  Without research-based management recommendations, millions of dollars can be lost as a result of decreased yields or seed quality, improper deployment of control recommendations, and/or increased insecticide resistance.  S1080 participants have the skills, facilities, and knowledge to develop and implement effective, user-friendly IPM programs for these pests and future insect pest problems.

Since 2018, this regional project has effectively addressed challenges posed by new pest species of unknown origin such as soybean gall midge (Gagne et al. 2019, McMechan et al. 2021) as well as insects that continue to expand their range, such as redbanded stink bug (Bundy et al. 2018), brown marmorated stink bug (Hamilton et al. 2018), and kudzu bug (Eger et al. 2018).  Additionally, soybean pests continue to develop resistance to insecticides, including soybean aphid to pyrethroids (Hanson et al. 2017).  Along with the changing pest complexes, soybean producers are also faced with managing pests with fewer tools and technologies, and at higher risks.  Renewed interest in cover crops and planting green add a new complexity to management of pest and beneficial arthropods in soybean.  A recent review shows several gaps in research and a need for multi-state projects with a consistent protocol (Carmona et al. 2021).  In addition, some states are experiencing a change from determinate to semi-determinate or indeterminate varieties that can alter the thresholds of existing pests (Schug et al. 2022).  With today’s market, soybean farmers are more reliant on insurance-based tactics as a result of uncertain commodity prices, the cost of production, insurance premiums, and changing weather.  This often leads to prophylactic treatments that are often mistimed or applied to sub-economic pest populations to prevent pest injury.  This leads to negative impacts on beneficial arthropods such as pollinators and predatory insects and to an increasing potential for resistance.  The widespread precautionary use of insecticides, in particular seed treatments, has led to contamination by neonicotinoid compounds in the soil and in plants in adjacent habitats (Hall et al. 2022).

Regional extension deliverables through participants of S1080 such as text alert systems (blackboard connect), pest management apps (aphid speed scout app), a pest specific website for soybean gall midge (soybeangallmidge.org), and 3D printing allow clientele to be engaged on multiple platforms to receive important information that is needed to increase awareness and aid in the decision making process.

Advantages of this Multi-State Effort

Soybean is grown in more than 29 states in the U.S. with many soybean insect pests distributed across state lines and provincial borders in Canada.  S1080 has worked synergistically to address invertebrate pest challenges across the U.S. and Canada with a significant benefit to the soybean industries.  A large number of the S1080 participants from several states have obtained grants and published together.  The combination of expertise and effort of multiple scientists across the region has resulted in the development of effective IPM solutions, and a clear and unified presentation of information among states.  This natural collaborative relationship between S1080 participants has led to the development and deployment of IPM programs for soybean defoliators, kudzu bug, stink bugs (Stink bugs on Soybean in the North Central Region), and soybean aphid (Krupke et al. 2017), with others anticipated in coming years (e.g., for soybean gall midge).

These research efforts are supported by experienced basic and applied research and extension entomologists who work in universities and government agencies from the various soybean producing states in the U.S. and provinces in Canada.  Participants maintain connections and collaborations through multi-state projects and with various state, regional, and national commodity organizations as well as with private industry.  Through the coordination of S1080, these scientists have an excellent record of developing and implementing effective IPM programs for major insect pests attacking soybean.  In 2009, the S1080 multi-state project (then named S1039) received the National Excellence in Multistate Research Award from the American Public Land-Grant Universities.  Based on these prior accomplishments, we feel strongly that our group is positioned to continue to deliver useful, science-based information to our stakeholders in the face of new and changing pest challenges.

Likely Impacts

This project will generate data on established and invasive soybean pest densities, distributions, and biology that are critical to improve overall national soybean IPM programs.  The group continues to focus on soybean gall midge, soybean aphid, Dectes stem borer, stink bugs, slugs, corn earworm, and insecticide-resistant Lepidoptera while continuing to scout, document, and control invasive soybean pests.  In general, the project will continue to prioritize maintaining a sustainable soybean IPM program, where sustainability is defined as pursuing maximal profitability in the short-term without sacrificing the potential for long-term stability of the system.  We will continue our focus on utilizing a combination of biological, cultural, physical, and chemical tools to regulate pest populations while minimizing environmental risks.