The Impact of Buckwheat Plantings on Releases of Parasitoid Wasps on a Dairy Farm

Progress report for GNC22-358

Project Type: Graduate Student
Funds awarded in 2022: $14,229.00
Projected End Date: 07/01/2024
Grant Recipient: Northern Illinois University
Region: North Central
State: Illinois
Graduate Student:
Faculty Advisor:
Dr. Bethia King
Northern Illinois University
Faculty Advisor:
Dr. Edwin Burgess, IV
University of Florida
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Project Information


This project will assess the capacity for buckwheat to increase rates of parasitism, and hence death, of house flies, Musca domestica, on dairy facilities in Northern Illinois with the augmentative release of parasitoid wasps. The pupal stage of house flies is attacked by several species of parasitoids. These parasitoids occur naturally and are sold commercially for augmentative releases. Recently, our lab has demonstrated that the house fly parasitoid, Spalangia cameroni experiences greater longevity and nutritional gain from buckwheat, at least in the laboratory (Taylor et al., 2021). Buckwheat is an inexpensive plant and our laboratory results suggest that it may benefit control attempts. The house fly is considered the most important pest of US dairy operations, costing the industry 500 million dollars annually in economic losses (Geden et al., 2021). US dairies make up approximately 25% of the total cash receipts of a $165 billion dollar animal production industry (USDA 2020). An Integrated Pest Management (IPM) approach to the control of house flies is needed because the flies have evolved resistance to insecticides (Freeman et al., 2019), and because insecticides can adversely affect non-target species (Main et al., 2018). Project outcomes include: 1) determine the impact of supplemental buckwheat, placed near where parasitoids are released, on rates of parasitism of house fly pupae and inform our farmer collaborators on parasitoid biological control generally and results of the proposed project specifically; 2) engage with local high school agricultural classrooms on dairy IPM, and capitalize on the students’ social media savvy and connections in creating outreach materials; 3) produce an extension handout of IPM of house flies on dairy facilities and distribute it through Illinois county farm bureaus and participating county extension offices. Buckwheat can improve biological control of crop pests. Whether this success translates to livestock facilities remains to be seen and is what makes this project novel.

Buckwheat borders have increased rates of parasitism and predation by some natural enemies of crop pests (Bianchi et al., 2006). For the proposed project, buckwheat will be placed around dairy cow housing with augmentative release of parasitoid wasps, and parasitoid monitoring stations will be used to gauge rates of parasitism. Each buckwheat plot will be paired with a non-buckwheat plot for comparison. Each plot will have a release of supplemental parasitoids. Pupae from the monitoring stations will be collected and observed for parasitoid emergence to determine rates of parasitism.

Project Objectives:

This project will involve working directly with dairy producers and a local agricultural class on aspects of house fly control, including how the use of insecticides can lead to resistant populations of house flies and how to implement an IPM program (learning outcomes). From the information provided by this study farmers will be able to institute practices that support natural enemies such as parasitoid wasps (action outcome). At the end of this project farmers and agricultural students are expected to better understand: 1) how resistance to insecticides evolve, 2) impacts of insecticides on non-target arthropods, 3) what parasitoid wasps are, and 4) methods to support those natural enemies of house flies. A local agricultural class will be able to practice science communication skills. They will have the opportunity to be creative in producing educational materials, making use of their social media savvy or producing more traditional materials to garner the attention of other young people or their parents/guardians. The materials generated by the agriculture classroom will be provided to the DeKalb County Farm Bureau. These materials will then be used to create an extension handout with the insight of the next generation of agricultural workers. As a result of this project, farmers will be informed about floral resources as an option for part of their pest management strategies.


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Materials and methods:

Farmer assisted the graduate student in determining three locations for the buckwheat patches that did not interfere with the normal operation of the dairy farm near the farmer identified areas of high house fly presence. 

Buckwheat flowers were greenhouse grown in two-gallon pots in a mix of 1:1 field loam to potting soil. Buckwheat plants will be maintained in the greenhouse until just before flowering. After the buckwheat has started to flower, ten pots per site, with a total of three sites, will be placed near rearing pens such that they will be near areas of ideal house fly breeding areas, but out of the way of farm workers. This work wascompleted during the time of peak of parasitoid activity in late August and early September (Olbrich and King 2003). Buckwheat pots was watered daily if needed based on if the soil was moist when checked.

Rates of parasitism and differential pupal mortality are being determined by using the modified sentinel monitoring described by Geden et al. (2020). Sentinel monitoring involves using screen bags of pupae to determine parasitoid presence and diversity as described in Rutz and Axtell (1980). This sentinel monitoring technique developed by Geden et al. has greater sensitivity to the presence of Spalangia spp. compared to the original sentinel bag monitoring technique described by Rutz and Axtell (1980). For each buckwheat plot, one monitoring station will be placed at 0 m, one at 1.5 m, and
one at 3 m away from the buckwheat pot. Each sentinel monitoring station will be replaced every 3 days for the 4 weeks of peak parasitoid activity, which is mid-August through early September in Northern Illinois (Olbrich and King 2003). The same thing will be done for each non-buckwheat plot, i.e., control, each control will be placed at least 15 m away from the buckwheat pot and in a similar environment. This distance
was chosen as S. cameroni is not known to disperse further than 5 m away from the placement site (Machtinger et al., 2015). 

The mortality rate of the house fly pupae will be examined by determining how many pupae in the sentinel bags do not produce flies. Deaths of fly pupae not exposed to parasitoids (by being in bags of finer mesh) will be subtracted to determine pupal deaths caused by the parasitoids (versus by failure of fly development that occurs even in the absence of parasitoids). How many parasitoids emerge from the sentinel bag pupae will also be measured. This work is currently ongoing.

Research results and discussion:

This part of the work is currently on going. 

Participation Summary
1 Farmers participating in research

Educational & Outreach Activities

4 Curricula, factsheets or educational tools
1 Webinars / talks / presentations

Participation Summary:

1 Farmers participated
1 Ag professionals participated
Education/outreach description:

Currently two outreach/science communication products have been created to provide students with an example of what they can produce as outreach materials for their class assignment. 

I will giving students an interactive talk on Tuesday March 19th where they will be provided a slideshow presentation, a worksheet, and an assignment related to IPM and natural enemies for filth fly control.  

Project Outcomes

2 Farmers reporting change in knowledge, attitudes, skills and/or awareness
1 New working collaboration

Information Products

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.