Distribution of <i>Leptocorisa chinensis</i>（Hemiptera: Alydidae）in the Coastal Area of Iwate Prefecture from Net-Sweeping Censuses in 2020–2023

To investigate the occurrence of Leptocorisa chinensis in its northernmost distribution area, we conducted net-sweeping surveys in the coastal region of Iwate Prefecture, Japan, from 2020 to 2023. These surveys were performed annually in early and mid-September, coinciding with the period when overwintering adults have almost completed their dispersal and expansion of habitat range and first-generation adults start to emerge. We sampled 12 to 20 locations in grassy fields dominated by poaceous plants, especially Echinochloa crus-galli（L.）P. Beauv. var. crus-galli. Data for L. chinensis were analyzed considering factors from neighboring regions that influence the occurrence and abundance of the species. Our survey indicated that the northernmost boundary of L. chinensis extended 70 km further north than previously reported. However, the analysis of the occurrence of L. chinensis against the average maximum temperature in early February and the distance from Japanese cedar forests （overwintering habitats） did not yield statistically significant results. This discrepancy may be attributed to differences in survey methods and generational variations of L. chinensis during the research period compared to earlier studies. Overall, L. chinensis has shown an expansion in its range, highlighting the need for ongoing monitoring and continuous surveys.