PS 33-143 - Ground beetle (Coleoptera: Carabidae) communities within KBS LTER prairie strips and surrounding row crop

Background/Question/Methods

Perennial prairie strips are a conservation strategy aimed at mitigating the detrimental effects of intensive agriculture while promoting biodiversity and encouraging ecosystem services. Ground beetles (Coleoptera: Carabidae) are important generalist predators in agricultural systems that prey on a variety of insect pests and weed seeds. Little is known about how prairie strips in US row crops may alter Carabid abundance, community structure and predation services.

We measured the abundance, richness, and community composition of ground beetles in newly-established prairie strips and the surrounding row crops using pitfall traps. Data were collected over a three year period within the prairie strips and at varying distances into the surrounding row crop. We expected ground beetle abundance and richness to differ 1) over time, as prairie strip vegetation establishes; 2) with crop management history (reduced-input conventional vs. biologically-based); and 3) with distance from the prairie strip.

Results/Conclusions

To date, I have identified 41 ground beetle species, including several abundant generalist predators and weed seed eaters. Total abundance increased from 2019(456) to 2020 (753). Abundance increased in the reduced-input conventional treatment, particularly for the late-season months of August and September. Both richness and abundance increased from 2019 to 2020 within the prairie strips, but less so into the row crop for reduced-input conventional and biologically-based treatments. I identified 34 species of ground beetles in 2019, and 34 species in 2020; however, 7 species were lost in 2019 and 7 species gained in 2020. Further research will investigate the functional traits of the identified species. Ground beetle community composition differed with crop management history and between two years of the study but did not appear to differ strongly with distance from the prairie strip.

Prairie strip establishment is usually a three year process. Data collection and sample processing are ongoing, and we expect to see further change in community composition, abundance, and richness of ground beetles in 2021. This analysis will frame future research questions for the provision of ecosystem services by ground beetles in row crops containing prairie strips.