Abstract: It is a common phenomenon of nature that insect shifts from one habitat to another by flight, while its seasonal long distance migration in space with air current occurs in a special environment. It is one of the unifications of insect and environment during the course of evolution. The fact that an insect migrates from A to B and finds a habitat in B is a random event, but the migration of an insect population complies with certain statistic regularity. Thus, the migratory insect gets the initiative adaptation to the environment by using a passive mode, the dispersion directed by air current.

Key words: insect migration, dispersion with air current, randomness, regularity