The rapid mandible strike of a termite soldier

SummaryArthropods use a remarkable variety of mechanisms to store energy for rapid ballistic movements [1–8]. These movements are primarily either for prey capture [1,2] or for predator evasion [3–5], although the mandible strike of the trap-jaw ant can produce both outcomes [6,7]. 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 [6,7], 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 [8,10]. The velocity achieved during the T. panamaensis strike exceeds those reported for other ballistic movements in arthropods [1–8] and generates sufficient force upon impact that a single blow can kill invaders within the narrow confines of their tunnels