Fig. 9
From: Drosophila pachea asymmetric lobes are part of a grasping device and stabilize one-sided mating
Measurement of tilting index parameters. Tilting index TIi (t) at a certain time point t in mating couple i was calculated by measuring the following parameters: a distance between the bases of the wings in the male during copulation d(M i ,t), b distance between the bases of the wings in the female during copulation d(F i ,t), c distance between the bases of the wings in the male in resting position d(M i , restingposition) and d distance between the bases of the wings in the female in resting position d(F i , restingposition). Note that measurements of flies in resting position were taken when they were positioned upside-down on the Plexiglas cover of the mating cell, to be certain that the flies were positioned on a horizontal surface