A Survey of the Dung-Dwelling Arthropod Community in the Pastures of the Northern Plains

Simple Summary The European settlement of North America has led to dramatic changes in the environment of the Northern Plains. As this ecosystem's plant and animal communities continue to evolve during this period of human-driven modification, it is important to continually measure the impact on important ecological groups in this system, such as dung-dwelling arthropods. Therefore, we report the dung-dwelling arthropod community collected from 40 pastures extending from northeast South Dakota to central North Dakota during the 2019 and 2020 grazing seasons. A total of 51,283 specimens were collected. Beetles, flies, and parasitoid wasps comprised the majority (94.5%) of the community. Pest abundance was low on average, with about one adult pest found for every two dung pats sampled, and most of the pats (80%) did not contain any adult pests. While there were many beneficial arthropods collected for this survey, the abundance of these beneficial species was inconsistent from one pat to the next and throughout the grazing seasons. Future work is needed to understand how to increase the consistency of these beneficial organisms in the grassland ecosystem of the Northern Plains.Abstract Grassland ecosystems of the Northern Plains have changed substantially since European settlement began in the latter half of the 19th century. This has led to significant changes to the dung-dwelling arthropod community in the region. As humans continue to modify large portions of the landscape, inventories of ecologically significant communities are important to collect in order to monitor the long-term effects of anthropogenic biomes. We conducted a survey of the arthropod community dwelling in cattle dung from 40 pastures extending from northeast South Dakota to central North Dakota during the 2019 and 2020 grazing seasons. In sum, 51,283 specimens were collected from 596 dung pats, comprising a community of 22 orders. Coleoptera, Diptera, and Hymenoptera contributed to the majority (94.5%) of the community abundance. The mean pest abundance was low per pat (0.43 adult pests/pat), with 80% of the pats not containing any adult pest. Ecologically beneficial dung-feeding beetles, predators, and parasitoids were abundant in the region, but it was an inconsistent community, which may hinder ecosystem services. This highlights the need for future work to understand the mechanisms to increase the consistency of dung pat colonization for improved consistency of ecosystem services in the region.