Meeting Abstract
Praying mantises (Mantodea) catch prey by rapid motion of their specialized forelegs, quickly ensnaring smaller insects. Due to the high speed requirements to catch quick prey items, a mantis must accelerate their limb segments rapidly, which depends upon mechanical power. While organisms can increase mechanical power output by increasing muscle mass, the alternative is to couple muscle with an elastic tissue to generate relatively greater power than could be attained with muscle alone. In this phenomenon, known as power-amplification, elastic potential energy is stored in elastic structures and rapidly released, resulting in power outputs beyond those of muscle, as seen in the flea jump. This research investigates the foreleg strike of the Chinese Mantis (Tenodera sinensis) capturing live prey (Periplaneta americana) to determine whether power-amplification is used in the mantis strike. In our preliminary data, we recorded two strikes at 700 frames/second with two Edgertronic high-speed cameras, tracked the points in three dimensions. In these strikes, the distal tip of the tarsus reaches an average maximum velocity of 0.746 m/s, with an average peak acceleration of 60.7 m/s2. These values suggest purely muscular actuation, though further evaluation is needed using inverse dynamics to compute joint angular acceleration, torque, and power across individual foreleg segments (coxae, trochanter, femora, tibiae, tarsi) to identify coordination and control patterns and which joints are primarily responsible for generating power. The apparent lack of power amplification in T. sinensis forelegs suggests that trade-offs may preclude some animals from using it, such as the dual function of T. sinensis forelegs for both prey capture and locomotion.
