Abstract: Studies on flight ability of seven-spotted lady beetle (SLB), Coccinella septempunctata L. and Asiatic lady bird (ALB), Harmonia axyridis Pall. are presented. Field-captured wintering generation beetles were flown on flight mills linked to a microcomputer data processing system.Variability of the flight performance among specimens was great. Al though 36.5% of SLBand 23.7% of ALBnever made a flight more than30 min., there were some individuals flying over 20 hr. in both species. The percentage of tested beet les made a sigle flight in excess of 6 hr. and 12 hr. was 9.4% and 1.2% in SLB, as opposed to 21.1% and 13.2% in ALBrespectively. With respect to the total amount of flight duration accumulated from the flights lasting longer than 30 min., there were 20.0% of SLB and 47.4% of ALB exceeded 6 hr.; and the proportion of individuals ex ceeding12hr. was 7.1% in SLBand 28.9% in ALB. The females of ALBperformed the greatest flight ability during the vitellogenesis stage. The maxmum sustained flights and distances of 22.45 hr. and 94.464 km for SLBand 24hr. and 92.550km for ALBwere recorded. The maxmum speed of flight was 2m/s for both species.

Key words: Coccinella septempunctata, Harmonia axyridis, Flight ability