Elastic Properties of the Mandible in Termites —Measurements of the Force Closing and the Strength of Mandible—

Abstract

We have investigated the force closing and compression strength of mandible to clarify the relationships between the material quality and the elastic property of the mandible among various termite species. The compression tests of mandibles have carried out coating with the epoxy resin. For example, the maximum load of Zootermopsis nevadensis is about 4.8N and that of Monchamus alternatus is 20N. We analyzed the buckling stress using the Tetmajer's formula, because the parameter λ' (= 1/√nI/A) was smaller than 100. The calculated result showed that the critical load was equal to the maximum compressive load. The elastic modulus were the range of 2–7MPa. The forces of closing of the mandibles with applying the air pressure were measured in various termite species. The air pressure of Z. nevadensis is about 0.7kPa, and that of M. alternatus is about 1.63kPa, whereas we have improved the measuring system with a load cell, and the force of closing mandibles of Z. nevadensis were about 4–5mN.