THE REPRODUCTION-FLIGHT SYNDROME AND THE INHERITANCE OF TETHERED-FLIGHT ACTIVITY IN THE COTTON-BOLLWORM MOTH, HELIOTHIS-ARMIGERA

To test the hypothesis that the flight activity of Heliothis armigera (Hubner) (Lepidoptera: Noctuidae) conforms to the 'oogenesis-flight syndrome', female moths from India and Malawi were flight tested on nights 2, 4 and 6 after eclosion, using a tethered-flight technique. Maximum flight activity in the Indian strain occurred on night 2, that of the Malawian strain was not significantly different on the three nights of flight. This difference is explained by the Indian females reaching reproductive maturity c. 48 h before the Malawian females. The existence of a 'reproduction-flight syndrome' was confirmed by flight testing males and females of different maturity status on the fourth night after eclosion. Immature moths flew significantly more than did either mature-virgin or mature-mated moths. The inheritance of tethered-flight activity in a late-maturing line of Malawian H. armigera was investigated. Significant estimates of heritability, by offspring on mid-parent regressions, were obtained for both the total flight time (0.39 +/- SE 0.083) and the longest flight (0.15 +/- 0.058). The significance of such tethered-flight data to noctuid migration in the field is discussed, and the conclusion drawn that the current experimental design does not index migratory flight satisfactorily.