Evaluating the origin and spread of spotted lanternfly ( <i>Lycorma delicatula</i> ) in Japan

Abstract Spotted lanternfly Lycorma delicatula is an emergent invasive agricultural pest native to China, and has invaded the Republic of Korea ([i.e., South Korea] first detected 2006), Japan (2009), and the United States of America (2014). Previous reports from the Republic of Korea and the United States on L. delicatula detail rapid population expansion and severe feeding damage to crop and non‐crop host plants following its invasion. In contrast, populations in Japan initially spread slowly and remained isolated to two prefectures (Ishikawa and Fukui) for 8 years post‐invasion without any reports of agricultural damage. Here we update the current known distribution of L. delicatula in Japan through field surveys and complete a comprehensive review of formally published literature and community scientist reports. Recently L. delicatula has expanded its range in Japan with six new prefectural detections in the last 2 years. Phylogenetic analyses were performed using whole mitochondrial genome sequences of specimens collected across Japan to elucidate the genetic makeup and potential source areas of these populations. Phylogenetic analyses suggest the putative area of origin of Japanese L. delicatula populations is the north‐central region of China, as opposed to the invasive populations in the Republic of Korea and in the United States, which both originate from the eastern region of China. Results presented here provide a better understanding of the factors influencing the invasion dynamics of L. delicatula , which could enable development of improved biosecurity, monitoring, and incursion management programs for this pest.