Meeting Abstract
The soldiers in different termite species, all considered eusocial, have evolved diverse defense mechanisms for enemy or predators; for those inhabit in soil, elastic snapping mandibles are observed in several termite genera. Previous study reported that the symmetric mandibles of Termes panamaensis soldiers could render a snapping speed of 67 m/s, ranked as top record with trap-jaw ants among bio-movements. In this study, we examined the snapping mechanics of twisted left mandibles in Pericapritermes nitobei soldiers to test previous hypothesis that such presumably derived asymmetric form could perform more violent strike due to greater elastic energy stored in single mandible. Without sufficient equipment to directly film the mandible snapping behavior, we set up ball-strike experiments, filmed at 1000 fps, and conservatively estimated the striking (snapping) speed using the law of conservation of energy. The ball was mostly hit when the deformed left mandible returned to its original position where all the stored elastic energy transformed into kinetic energy. The estimated snapping speed had a mean of 55 ± 21 m/s (n = 6); half of the subjects could snap faster than 80 m/s and the maximum was 97 m/s. A recent filming trial at 460 kfps yielded result of 130 m/s, which sets the new record in bio-movements and proves our method a feasible and credible alternative for fast motion analysis. Comparison of mandible snapping mechanics not only allows us to examine termite soldier’s defensive strategy and their ecological-evolutionary consequences, but also provides insights to bio-inspired elastic structures and strong materials.
