Contributions of Dung Arthropods to Sustainable Pest Management in Rangeland Systems of the Northern Great Plains

View the project final report

Commodities

• Animals: bovine

Practices

• Pest Management: contributions of dung arthropods

      Dung beetles and other beneficial insects in cattle dung are a very important contributor to the health of pastureland. It is a diverse group of insects that recycles animal dung into the soil and reduces pathogens and parasites associated with dung. The ecological services that these insects provide are well documented, but the implications of current herd management practices such as ivermectin parasiticides have received little recent attention. The proposed research will provide a better understanding of the magnitude of contributions that dung arthropods have on dung degradation rates, as well as how current pest management practices in rangeland affect these services. The experiments in this project include describing dung community species richness and abundance in ivermectin treated and untreated farmland. Risk assessments on key dung beetle species and beneficial parasitoid wasps will also be conducted to identify potential threats to these groups of beneficial insects. Dung removal rates in the treated and untreated farms will be observed to identify correlation between the services that dung beetles provide and the presence of ivermectin. These dung arthropods are paramount to the success of sustainable agriculture and it is necessary to fully understand the importance that they have on pasture ecosystems in the Northern Great Plains. Knowledge of the effects that ivermectins can have on dung arthropods is needed to assess if there is any potential hazard to their use.   This information will eventually be used as a tool for farmers that allows them to manage the benefits that biodiversity provides to rangeland.        This project will describe the abundance, diversity, and services of dung arthropods (especially dung beetles and filth fly parasitoids) in the Northern Great Plains and conduct risk assessments of ivermectin on these insects. Dung arthropod populations will be recorded in untreated and treated pastures to identify differences in dung removal rates and pest populations. Laboratory tests of lethal and sub-lethal effects of ivermectin on dung beetle and filth fly parasitoids will support the field research.

There is a very limited amount of experiments and data available on the presence of dung arthropod communities when ivermectin treatments are used. The experiments conducted in this risk assessment will provide this knowledge. We will gain an understanding of what dung communities are present and how treatments in cattle alter the way the communities function. This will be a useful tool to allow ranchers to see if there is any risk to damaging beetle populations using ivermectin and if the benefits of a healthy insect community outweigh the use of parasiticides. The current estimates of benefits provided by these insects are likely undervalued due to the changes in the way cattle production systems run today. Field and laboratory experiments will be combined to give this “big picture” view of the impacts that management practices are having on the environment. Rancher will have access to this information and be able to use it to promote environmentally sustainable and economically viable operations for themselves and future generations. 

Data collected from the experiments will be analyzed and measured based on factors described in the methods. Regular meetings with my thesis committee will ensure that project goals are being met. The collected data will be summarized in peer reviewed publications that will result from the completed research. These publications will be translated in to extension work that will be a resource for farmers to conserve and manage dung beetle populations present on their farmland.  

For maximum relevancy, the proposed research will be conducted on operating ranches and this requires close contact with farmers. Every effort will be made to educate these farmers in the procedures and outcomes of the experiment so that these ranchers can be mouthpieces for the resulting research. Resources to aide farmers such as pictorial representations of dung beetles commonly found in the area will give them a reference to use when scouting for beetles in their pastures. Research findings will be presented at large gatherings or meetings attended by cattle growers and landowners (Cattlemens’ Association, Grassland Coalition, etc.).