Book excerpt: Many of the world's most serious agricultural pests are highly migratory. Through the use of special-purpose radars we are provided with insights into their movement and how they learn about and navigate through their environment. This text examines the behaviour and regional variations of these species, as well as the altitude of migration, concentration of insects in layers and how they respond to large and small-scale wind systems. The book relates radar observation of insect movement to complementary and competing methodologies and surveys its capabilities and limitations. It also deals wi