The East Asian Insect Flyway: Geographical and Climatic Factors Driving Migration Among Diverse Crop Pests

he East Asian Insect Flyway is a globally important migration route stretching from the Indochina Peninsula and the Philippines through East China to Northeast China and northern Japan, although most migrants utilize only part of the flyway. In this review, we focus on long-range windborne migrations of lepidopteran and planthopper pests. We outline the environment in which migrations occur, with emphasis on the seasonal atmospheric circulations that influence the transporting wind systems. Northward movement in spring is facilitated by favorable prevailing winds, allowing migrants to colonize vast areas of East Asia. Migrants may be subject to contemporary natural selection for long flights as succeeding generations progressively advance northward. Overshooting into far northern areas from which there is little chance of return seems common in planthoppers. Moths are less profligate and have evolved complex flight behaviors that can facilitate southward transport in autumn, although timely spells of favorable winds may not occur in some years.