Does local-scale grassland restoration affect lady beetle (Coccinellidae) communities?

Native lady beetles (Coccinellids) are declining in North America, because of anthropogenic habitat loss and fragmentation as well as displacement from non-native lady beetles, such as the seven-spot (Coccinella septempunctata). Evans (2000) hypothesized that native coccinellids are experiencing “habitat compression,” where native coccinellids are being pushed out of their ideal habitat and into less ideal peripheral habitats. Native coccinellids were previously found to prefer prey-rich agricultural areas, but due to displacement from highly competitive non-native coccinellids, native coccinellids may be persisting in semi-natural habitat with less prey and competition. Ecological restoration can improve habitat connectivity and supplement the total area of native-dominated ecosystems in a region. With a team of undergraduates, we established study sites from 2017-2019 to test if native coccinellids in Santa Barbara, CA, USA, were experiencing habitat compression. Coccinellids were observed for 28 weeks of each year within nine historic grasslands which were separated into three grassland classifications: restored, non-restored, and remnant, and ambient environmental conditions at each site to account for tree canopy cover, ground coverage, and plant and floral composition. Semi-structured management interviews were completed with land managers from each site to determine if management practices were related to lady beetle community differences. Results showed that lady beetle communities were slightly different within restored, non-restored and remnant grasslands. Different site types had different network modularity and complementarity, as well different dominant species. In conclusion, we found certain management focuses were correlated with native and non-native coccinellids, regardless of restoration status.