The fall armyworm,Spodopterafrugiperda,is a species native to the Americas and has spread to many countries in Africa and Asia in recent years.Proactive actions for potential invasion of S.frugiperda to China coordinated by govement agencies and agricultural extension systems resulted in timely detection in January 2019 in Yunnan province neighboring onto Myanmar.The extensive monitoring in southe provinces of China since February 2019 resulted in dynamic tracking ofS.frugiperda spreading to 13 provincial regions in China within 4 months by May 10,2019,which is crucial for timely management actions in the fields.The first detections of S.frugiperda (co strain) in China were confirmed using cytochrome oxidase subunit 1 (CO 1) and triosephosphate isomerase (Tpi) genes molecular marker method.In addition to S.frugiperda,larvae of three other noctuid species with similar morphological appearance (S.litura,S.exigua and Mythimna separata) can occur simultaneously and cause similar damage in cofields in southe China.Thus,we can use both morphological and molecular marker methods to compare larval stages of four noctuid species.Further,we discuss the risk of potential spread of invasive S.frugiperda to other regions and impact on co production in China.