Abstract:The flight capacity of the Asian Corn Borer （ACB） was determined in laboratory bY tethered-fligit techniqae, in which a flight mill, a circulaw wind tuunel and a microcomputer processing system was established. The effects of the age, sex, weight of pupa, temperatures, moisture, and wind speed on the flight capacity of ACB were tested. The possibility of the migratory movements of ACB was discussed.
The strongest flight of the moths occur at 10—48h old in females and 3—day—old in males. During 24h tethered flight on the mill, the total flight duration and distance of the 2—day—old females are 23 hour and 120km on the average. During 48h, they can fly 39.8 h and 179 km. the longest single flight can be sustained for 32.8 h without any break. The average flight speed is 1.54 m/s and the maximum is 2.42 m/s in still air（all the data are original records without any drag calibration）. The moths emerged from the pupae weighed from 71 to 119 mg showed a higher flight capacity. Temperature range from 20 to 30℃ is suitable for flight. Flight range and duration decline greatly at low R. H when tethered in a circular wind tunnel,their own flight speed reduce gradually with the increasing of the wind speed and they stop wing beat when the wind speed is more than 9m/s. They can make upwind flight when the wind speed is less than 1.53—1.6m/s.
There is no apparent difference in behavior on the mill when the tests were conducted both during the day and night. The fact that the moths have showed no similar temporal patterning of the behavior in the laboratory and in the field may be a consequence of the greater susceptibitity of the insect disturbed by the experimental conditions. Even so, these various indices obtained from the tests are valuable for themonitoring, forcasting and controlling of ACB.
