The long‐distance migration of Nilaparvata lugens (Stål) (Delphacidae) in China: radar observations of mass return flight in the autumn

摘要: Abstract. 1A case study is presented of the autumn migration brown planthopper, Nilaparvata lugens (Stal), in area Nanjing People's Republic China. The was made using a high frequency (8 mm wavelength) radar and net suspended from kytoon. 2The observations confirmed that long-distance return migrations occur China mid late September, with N.lugens being carried on prevailing north-easterly wind towards infestation overwintering areas species. 3After mass take-off afternoon or at dusk, migrants flew for several hours during evening, often dense layer which formed heights between about 400 1000m above ground. These layers had well-defined ceilings corresponding to an air temperature 16°C. height top surface inversion, i.e. did not fly warmest air. 4The concentrations overflying were backtracked source up 240 km away north-east Jiangsu Province. Planthoppers observed emigrating would reach south Anhui Province north Jiangxi if they 12 h. 5There second period dawn. Insect sometimes but last longer than 1–2h. 6The present results strikingly different those previously dry season Philippines, where migratory flight durations largely confined periods 30min dusk dawn. 7Our are discussed relation equator-wards undertaken by other insect species, importance these maintenance long-flying genotypes populations considered.