Interpretation of the flight activity of Nilaparvata lugens (Stål) and Sogatella furcifera (Horváth) (Hemiptera: Delphacidae) based on comparative trap catches and field marking with rubidium

Detailed studies were conducted over a five-year period at a rice farm in the Philippines on the flight activity of Nilaparvata lugens Stål) and Sogatella furcifera (Horváth). Suction traps were used to measure aerial density, and catches included immigrants, emigrants and insects undertaking trivial flight. Activity was partitioned using a variety of other trap types. Emigration was effectively monitored using net canopy traps and immigration was best measured using green water traps. Yellow water traps also measured immigration, but when macropterous adults were being produced within the plot, insects undertaking trivial flight were also caught. The light-trap caught immigrant and over-flying migrant insects.