Abundance and Seasonal Migration Patterns of Green Lacewings (Neuroptera: Chrysopidae) across the Bohai Strait in Eastern Asia.

Simple Summary: Green lacewing is an important natural predator of many crop pests. In this study, we conducted 10 years of monitoring from 2012 to 2021 to determine the aerial migration patterns of green lacewing species using a suction trap on Beihuang Island (BH), a small island in the center of the Bohai Strait that serves as a seasonal insect migration pathway in eastern Asia. Overall, there were significant interannual and seasonal differences in the densities of the main species, and the sex ratio varied among different months, with more females being captured than males. It was determined that the green lacewings primarily originated from Shandong Province through trajectory analysis. This study provides valuable insights into the migration dynamics of green lacewings in eastern Asia, which is helpful for biological control in the region. Many insects, including green lacewings, migrate seasonally to exploit suitable breeding and winter habitats. Green lacewings are important natural enemies of insect pests worldwide. Here, four dominant green lacewing species, Chrysoperla nipponensis (Okamoto), Chrysopa pallens (Rambur), Chrysoperla furcifera (Okamoto), and Chrysopa formosa Brauer, were investigated for their ability to migrate between northern and northeastern China across the Bohai Strait from late May to late October each year. Furthermore, there were significant interannual and seasonal differences in the number of migratory green lacewings collected. The number of green lacewings in spring was significantly lower than that in summer and autumn, and the highest average number of green lacewings occurred in June. In addition, there were differences in the sex ratio of migrating green lacewings between months, with a greater proportion of females than males. Finally, the seasonal migration trajectories simulated by the HYSPLIT model revealed that the green lacewings captured on Beihuang Island primarily originated from Shandong Province. Accordingly, these findings contribute to our understanding of green lacewing migration in eastern Asia and aid its incorporation within integrated pest management (IPM) packages for several crop pests. Furthermore, long-term tracking of migrant insect populations can reveal ecosystem services and trophic dynamic processes at the macroscale. [ABSTRACT FROM AUTHOR]