Fig 10. Aerodynamic forces estimated from the quasi-steady analysis.

A) Lift forces. B) Horizontal (thrust) forces. Red and blue colors denote the left (internal) and right wing, respectively. Both forces are normalized with the beetles’ body weight. Thrust/drag is defined as positive and negative when directed forwards and backwards, respectively. The insert above B shows the yaw torque due to asymmetric flapping that should lead to exiting the circular flight trajectory in free-flying beetles.