Fig. 6. Latency (main panels A—C) and phase (insets in A—C) of the onset of tegula activity in the wingbeat cycle and their relationship to wing stroke parameters (see Fig. 2) in the fore- (i) and hindwing (ii) (data from four individuals shown, each in a different colour). (A) In both pairs of sense organs, latency depends on the downstroke interval (P<0.05; solid regression lines). However, the phase of tegula activation was not related to cycle period (P<0.05; broken regression lines). (B) Neither the latency nor the phase of the tegula discharge depends on stroke amplitude (P>0.05). (C) The relationship between the latency of tegula activity and wing angular velocity is non-linear (r² significantly different from zero, P<0.01). Within the range of angular velocities observed, latency approaches or reaches a minimum value at higher angular velocities. In contrast, the phase of tegula discharge is almost independent of angular velocity. For details, see text. Relationships for all animals investigated are given in Table 1.