Recipient Organization
SOUTH DAKOTA STATE UNIVERSITY
PO BOX 2275A
BROOKINGS,SD 57007
Performing Department
Plant Science
Non Technical Summary
In South Dakota, agricultural production accounts for a large portion of the state's annual revenue. However, agricultural production is challenged annually by insect pests of the major agronomic crops. These insect pests may be invasive or native, and may also be established or emerging. For example in 2015, a new pest of soybean was first detected in South Dakota. In 2018, it was determined that this species was the soybean gall midge and it was a previously undescribed species of insect with no natural history information.To further complicate the management of insect pests, there have been documented cases of insecticide resistance in the populations of major insect pests of corn, soybean, sunflower, and alfalfa in South Dakota. The goals of this project are to: 1) provide precision-based insect pest management recommendations to South Dakota stakeholders, and 2) provide South Dakota stakeholders with recommendations regarding management of insect resistance. This will be accomplished through the completion of annual insect population surveys, efficacy trials, and insect susceptibility assays. Degree-day models will be developed and tested to provide stakeholders with additional tools for prediction insect activity. Winter mortality predictions will also be developed to assess the impact of winter conditions on insect populations to provide stakeholders with estimates for the value of insecticide seed treatments and in-furrow insecticides.A key outcome of this project will be reduced input costs for crop production, while also providing environmental benefits. For example, the information provided to stakeholders will reduce prophylactic insecticide applications. It will also reduce ineffective insecticide applications, which result in development of insecticide resistance and detrimental effects on non-target species. This project will also provide scouting and management recommendation for new and invasive insect pests.Results from this project will be disseminated to South Dakota stakeholders with an emphasis on stakeholders involved with agriculture. In addition, the information will be presented and made available to scientists and industry professionals at regional and national scientific meetings. Producer focused outreach activities will include: field days, field schools, and webinars. The data will also be used to create peer-reviewed publications, extension articles, fact sheets, identification guides, pest management guides, and best practice management guides. These publications will assist stakeholders with making accurate insect identifications and also provide up-to-date management recommendations to ensure that an integrated pest management approach is being used. This, in turn, will reduce prophylactic or ineffective insecticide applications.
Animal Health Component
90%
Research Effort Categories
Basic
10%
Applied
90%
Developmental
(N/A)
Goals / Objectives
Objective 1. To provide precision-based insect pest management recommendations to South Dakota stakeholders.This objective will be accomplished through the completion of the following tasks: 1) monitor major and minor South Dakota crops for insect pest populations, 2) conduct efficacy trials to provide best management recommendations, 3) conduct research to determine the phenology of major insect pests, 4) conduct insect pest surveys in South Dakota using various trapping methods to monitor seasonal insect pest populations, and 5) disseminate findings through peer-reviewed and extension publications.Objective 2. Provide South Dakota stakeholders with recommendations regarding management of insect resistance.This objective will be accomplished through the completion of the following tasks: 1) assay insect populations from major crops to determine levels of susceptibility to commonly used foliar insecticides, 2) evaluate host plant resistant traits for major crops, 3) evaluate alternative management strategies for insects with reduced susceptibility, and 4) disseminate findings through peer-reviewed and extension publications.
Project Methods
Objective 1. To provide precision-based insect pest management recommendations to South Dakota stakeholders.Data will be collected from insect surveys, field experiments, and efficacy trials. For surveys, insects will be collected on a weekly or monthly basis, depending on the crop and insect species, during the growing season. Insect surveys will be conducted in areas where the crop affected by the insect is grown. Surveys will be conducted on insects that have known population fluctuations (e.g., grasshoppers), are newly identified pests (e.g., soybean gall midge), or are routine pests (e.g., soybean aphids, red sunflower seed weevils, and alfalfa weevils). These surveys will be conducted in targeted regions within the state or statewide, depending on the insect species.Collection techniques will vary by crop and insect species but may include sweep net collection, black light trap, or baited pheromone stick cards. Sample collections for each survey will be collected by SDSU farm managers and their staff, SDSU Extension Agronomy specialists, regional agronomists and/or crop consultants, and the SDSU IPM Coordinator. Population data from the surveys will be compiled and used to generate scouting recommendations for South Dakota stakeholders within a week of the data collection. This will provide stakeholders with timely pest recommendations based on current population data. The information collected from these surveys will also be used to produce guides for scouting and management, which will be published within 1-2 years of the data collection.Efficacy trials will be set up using field research plots on SDSU Research Farms and when applicable on stakeholder fields (e.g., soybean gall midge, red sunflower seed weevil). Efficacy trials will be placed in areas of the state where pest populations are currently causing yield loss, or field failure reports originated from. The size and number of the plots will vary by crop and the number of products being tested. Pest populations will be monitored prior insecticide application. Population data will also be gathered post-application. The pre- and post-treatment populations will be compared to determine the effectiveness of the treatments. Treatments will be applied using a small plot sprayer or backpack sprayer depending on the crop and crop height at the time of insecticide application.Phenology data for major insect pests will be generated in both field and laboratory settings. The insects will be monitored throughout a growing season to determine factors that trigger emergence, activity, and spread. To collect this data, emergence cages will be placed into previously infested fields and will be monitored weekly to detect first emergence and last emergence for the overwintering population. Sticky cards and emergence cages (i.e., for multivoltine insects) will be used to monitor populations within the current crop. Direct observations and sampling will also be used to monitor the development on the crop. Weather data from local Mesonet sites will be collected, along with cropping history data for each site.Insect emergence and activity data will be compared to weather data and cropping history to determine the extent and degree of any correlations. For example, the impact of soil and air temperature (degree days) is expected to correlate with emergence and oviposition. When applicable, existing models will be analyzed to determine accuracy. For insects that have no existing models, models will be developed to generate algorithms that could provide producers with decision making tools regarding treatment options and timing based on insect activity and population density. Data on insect winter mortality will be calculated for major pests using weather data. Additional mortality predictions will be developed for major insect pests that overwinter in South Dakota (e.g., soybean gall midge, red sunflower seed weevil). The data collected will be used to provide stakeholders with estimates of insect activity to reduce scouting when insects are not active and encourage scouting when insect populations are present in the field.Objective 2. Provide South Dakota stakeholders with recommendations regarding management of insect resistance.Susceptibility assays will be conducted by collecting insect populations from the field and testing them in treated glass scintillation vials. Insects will be collected from fields prior to insecticide application to reduce the likelihood of testing individuals with a higher likelihood of reduced susceptibility. Sampled fields will include those near areas with previous field failure reports as well as areas without any reports. Testing near field failure reports will provide evidence of potential resistant populations. Evaluating additional areas throughout the state will provide an indication of the overall susceptibility of the insect pests to commonly used insecticides. Once collected, the insects will be maintained in a container with food and water for 24 h. The insects will then be placed into glass scintillation vials that were treated with technical grade insecticide active ingredients. Insects will be evaluated every 12 h for a 48 h period to determine the efficacy of the products. Insects that are moving with the vials will be categorized as alive. Those that are lethargic or twitching will be labeled moribund. Those that have succumbed to the insecticide treatment will be labeled as dead. For analyses, moribund insects will be included in the dead values. Abbott's Corrected Mortality will be used to account for any handling or environmental mortality. Briefly, the final populations in the untreated control are used to correct the mortality of the treatments. If reduced susceptibility is observed for an insect, a dose response curve will be established for each of the tested insecticides. This will use similar methods but will include six concentrations of each insecticide to determine the level of resistance present in the population.Insect resistant plants that have been bred and engineered with specific resistance or insecticidal genes will be evaluated when varieties containing host plant resistance become available. Efforts to evaluate soybean varieties that have been developed with aphid resistance traits will be conducted. Research plots will be established at SDSU Research Farms to evaluate the soybean varieties. Soybean aphid populations will be scouted weekly and enumerated to determine if differences in population densities exist among the treatments. Yield will be collected at the end of the season to ensure that there are no agronomic restraints associated with the inclusion of the resistance genes.