In late 2018,the fall armyworm (FAW) Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) made its arrival in China and its populations have since proliferated across most of eastern Asia.While S.frugiperda exhibits a considerable dispersal capacity and engages in long-distance migration,there's only scant information on the species' flight capability.Here,we empirically assessed S.frugiperda flight activity under varying climatic conditions using a flight mill.More specifically,under laboratory conditions,FAW exhibited superior flight performance at 20-25°C and 60-90％ relative humidity (RH).When quantifying flight performance over five consecutive nights (i.e.,10 h/night),all flight parameters initially increased and then gradually dropped and FAW adults attained a total flight distance,duration and velocity equal to 63.73 km (48.42-94.12 km) (median,quartile range),24.12 h (20.87-27.73 h) and 2.73 km h-1 (2.13-3.33 km h-1),respectively.Our work constitutes a first comprehensive assessment of S.frugiperda flight performance and provides baseline information for future efforts to forecast spatiotemporal changes in its geographical distribution,movement patterns and invasion trajectories.Such can ultimately permit a timely and targeted deployment of area-wide pest management measures against this newly-invasive pest in China and across eastern Asia.