Some mechanical properties of the flagellar-pedicellar suspension in Aedes aegypti (L.)

Abstract The rotation of the flagellum of male and female Aedes aegypti (L.) was measured in a wind tunnel at wind speeds between 0 and 116cms^-1. Although the surface area of the female flagellum is only 10% of the male, it rotates through double the angle of the male flagellum for the same increase in wind speed. The larger rotation of the female flagellum could result from: a reduced resistive torque in the flagellar-pedicellar suspension; a larger antennal-positioning reflex; a smaller initial angle of attack. The resistive torque in the flagellar-pedicellar suspension was measured in both male and female Aedes aegypti. In ten adult females the average torque at 8^o rotation was 2.70 ± 1.33 times 10^-10Nm and in ten males it was 6.46 ± 3.46 times 10^-10Nm. The significance of these results is discussed with reference to the sexual dimorphism in the sensory tasks required of Johnston's organ in the two sexes.