Tracking and chasing in houseflies (Musca): An analysis of 3-D flight trajectories

The flight trajectories of free flying female and male houseflies have been analyzed in 3 dimensions. Both female and male flies track other flies. The turning velocity agr (around the vertical axis) is linearly dependent upon the horizontal angle psgrF (that is the angle between the trajectory of the tracking fly and the target) for small values of psgrF in females and for the whole range of psgrF in males. The 3-dimensional velocity ugr xyz of the chasing fly is linearly dependent upon the distance between leading and chasing fly in males but not in females. Male chasing thus appears to be more efficient than female tracking. It is shown that earlier assumptions on visual control of flight in female flies derived from experiments on fixed flying flies are justified