Figure 2.

Left–right timing differences in pairs of power muscles. (a) Dorsolongitudinal muscles (downstroke: DLMs) and dorsoventral muscles (upstroke: DVMs) power moth flight indirectly via deformation of the thoracic exoskeleton. (b) With the moth tethered to a torque meter, we recorded from both left–right pairs of muscles as the moth turned in the yaw (left–right) plane. (c) Electromyograms showed active muscle potentials (‘spikes’) from each muscle that were easily discriminable (orange dots) using threshold crossing (orange dashed line). During each wingstroke (grey dashed lines; defined by the right DLM spiking), we measured the time difference between the left and right discriminated spike in each muscle pair.