Take-off Behavior of the Alatae in Aphis gossypii Glover (Homoptera: Aphididae)

Abstract

Aphids at the late larval stages were collected from laboratory colonies that had been reared on Veronica persica. The larvae were placed in petri dishes, and every hour, they were observed and the number of winged adults was counted in the laboratory. Aphids showed the same molting behavior both in the daytime and at night. Newly formed winged aphids were transferred on cut papers inside a test cup and every hour of the take-off behavior was observed. Aphids took off mainly after 10–24 h, though the range of the period preceding flying ranged from 1 to 31 h. Many young adults took off from 7: 00 (around sunrise) to 14: 00. This observation was accounted for the findings because aphids that molted from the day time to the night took off concentrically in the next day. Newly formed winged aphids were transferred on fresh host plants inside a test cup and every hour the plants were observed and the number of individuals which took off was counted. Time of take-off in the aphids was delayed composed with the condition in which host plant were absent: a few newly molted adults took off on the day of emergence, which most aphids took off on the next day, and the number of individuals which took off gradually decreased thereafter. None of the molted adults produced offsprings on the same day, 40% of the adults produced offsprings on the next day and the ratio and number of offsprings per adult increased with time. © 1987, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.