Meeting Abstract
The take-off of Bemisia tabaci is executed by a powerful jump that launches the insect into the air while its wings are still in a resting position, i.e., pointing backwards along the sides of the body. We show that the take-off jump from a flat and uniform surface results in forward rotation of the body in the pitch plane. However, the insects manage to stop body rotation even before spreading their wings and flapping them. When the wings start to deploy, the rotation of the body reverses direction abruptly. We explored the mechanism behind this righting ability by modeling the dynamics (rigid body) of the aerial phase of the take-off jumps up to the point where the wings start to flap. We show that the contribution of aerodynamic force on the closed wings to stop and even reverse body rotation exceeds the contribution of the torque on the body by an order of magnitude. The distal half of the closed wings, which is located posterior to the body, contributes more than 80% of the aerodynamic torque. Once the wings deploy the torque responsible for righting increases but the predictability of the model is reduced suggesting that internal torques can also be at play at that phase. The righting response is extremely fast (<10 ms) underlining the effect of large surface area relative to body inertia in small creatures.
