Summary of the strain and timing of activation of the dl1muscles recorded during flight
| Moth . | Wing-beat frequency (Hz) . | Phase of activation . | Lop/Lr . | Strain amplitude (ΔL/Lo) . | Shortening duration (%) . | f2 (% of f1) . | N . |
|---|---|---|---|---|---|---|---|
| 1 | 25.6±0.8 | 0.45±0.02 | 0.99 | 0.055±0.003 | 46±2 | 5.5 | 59 |
| 2 | 22.3±0.8 | 0.49±0.02 | 0.95 | 0.125±0.005 | 60±4 | 29 | 106 |
| 3 | 23.5±0.4 | 0.48±0.01 | 0.99 | 0.065±0.001 | 44±1 | 46 | 93 |
| 4 | 23.2±0.8 | 0.56±0.03 | 0.96 | 0.131±0.005 | 54±1 | 12 | 92 |
| 5 | 22.4±0.6 | 0.50±0.03 | 0.97 | 0.040±0.003 | 47±3 | 13 | 88 |
| 6 | 21.1±0.5 | 0.45±0.01 | 1.00 | 0.080±0.004 | 41±2 | 42 | 105 |
| Mean | 23.0±1.5 | 0.49±0.04 | 0.98±0.02 | 0.090±0.031 | 45±5 | 25±17 |
| Moth . | Wing-beat frequency (Hz) . | Phase of activation . | Lop/Lr . | Strain amplitude (ΔL/Lo) . | Shortening duration (%) . | f2 (% of f1) . | N . |
|---|---|---|---|---|---|---|---|
| 1 | 25.6±0.8 | 0.45±0.02 | 0.99 | 0.055±0.003 | 46±2 | 5.5 | 59 |
| 2 | 22.3±0.8 | 0.49±0.02 | 0.95 | 0.125±0.005 | 60±4 | 29 | 106 |
| 3 | 23.5±0.4 | 0.48±0.01 | 0.99 | 0.065±0.001 | 44±1 | 46 | 93 |
| 4 | 23.2±0.8 | 0.56±0.03 | 0.96 | 0.131±0.005 | 54±1 | 12 | 92 |
| 5 | 22.4±0.6 | 0.50±0.03 | 0.97 | 0.040±0.003 | 47±3 | 13 | 88 |
| 6 | 21.1±0.5 | 0.45±0.01 | 1.00 | 0.080±0.004 | 41±2 | 42 | 105 |
| Mean | 23.0±1.5 | 0.49±0.04 | 0.98±0.02 | 0.090±0.031 | 45±5 | 25±17 |
All values were calculated for each wing stroke cycle and averaged for the total number (N) of complete cycles within each flight bout. Phase of activation is the time from the start of muscle lengthening to the peak of the spike in the EMG record, divided by the cycle period. Lopis the operational muscle length, defined as the midpoint between the maximum and minimum length in each cycle. Lr is the rest length of the dl1muscles. ΔL is the difference between the maximum and minimum length in each cycle. Shortening duration is the duration of muscle shortening expressed as a percentage of each cycle period. The amplitude of the 2nd harmonic of the Fourier-transformed strain record is expressed as a percentage (f2) of the amplitude of the 1st harmonic. Values are given as means ± s.d.