Abstract:
Arthropods use a remarkable variety of mechanisms to store energy for rapid ballistic movements []. These movements are primarily either for prey capture [] or for predator evasion [], although the mandible strike of the trap-jaw ant can produce both outcomes []. Soldiers of the termite Termes panamaensis (Snyder) also have a mandible strike [[9]]. We report that this mandible strike is a rapid, ballistic movement that functions neither for prey capture nor for predator evasion, but as a defence for the colony against insect invaders such as ants or other termite species. Unlike that of the trap-jaw ants [], the mandible strike of T. panamaensis soldiers involves a scissor-like movement of highly elongated mandibles across one another, powered by energy stored in deformation of the mandibles, a mechanism convergent with the mandible strike of the ant Mystrium[]. The velocity achieved during the T. panamaensis strike exceeds those reported for other ballistic movements in arthropods [] and generates sufficient force upon impact that a single blow can kill invaders within the narrow confines of their tunnels.
