The Mechanics of the Predatory Strike of the Praying Mantid Heirodula Membranacea

The mechanics of the predatory strike of Heirodula membranacea (Burm.) have been studied using high speed ciné, electrophysiological and anatomical techniques. Calculations of the muscle output required to produce the strike suggest that muscle performance generally lies within the range observed elsewhere and that no specializations for prior energy storage, as are found in some other rapid insect movements, are necessary. This view is supported by simultaneous EMG and ciné studies showing no significant delay between the onset of EMG activity and the onset of stress development required by the direct action model. The apodemes of a number of forelimb muscles are found to have complex two-point suspensions; these have a significant role in determining the moment-arm/joint-angle relationships of the muscles. The parallel-fibred part of the tibial flexor muscle has a high strain rate, 17·5 s−1, at 27–30°C. This is the fastest recorded strain rate for an insect muscle, and approaches the fastest strain rates of mammalian muscles operating at 37 °C.