• aerodynamic power;
  • flapping;
  • flight trajectory;
  • Satyrinae;
  • wing pause


The skipping flight patterns of three species of Ypthima (Lepidoptera: Nymphalidae) were analyzed using high-speed video recordings to clarify how wings move and how driving forces are produced. All three species showed a flight pattern that includes a pause that accounts for about 50% of a flap cycle when their wings completely close after each upstroke. The observed pause causes the “skipping” flight trajectory based on the clap–fling mechanism. Pause duration was correlated with upstroke wing motion, suggesting the contribution of the latter to a long pause duration. This is also supported by the temporal relationship between the wing and body motions. The aerodynamic power necessary for the pause flight was calculated for the three species.