1.Characteristics of Migratory Activity Migratory process is an instinctive habit. *Emigration flying occurs at special times Daytime pests flying during day; Nighttime emigration:moths; Dust emigration:brown rice planthopper Nilaparvata lugens. Directional flying in swarms ™ Migratory process is an instinctive habit. ™ Emigration flying occurs at special times Daytime : pests flying during day; Nighttime emigration: moths; Dust emigration: brown rice planthopper Nilaparvata lugens. ™ Directional flying in swarms 1. Characteristics of Migratory Activity Characteristics of Migratory Activity