Abstract
The aim of this second paper is to elucidate the relation between morphology of flight muscles and function of wings. The paper describes two experiments: measuring the structural characteristics of thoracic exoskeleton in the indirect-flight-muscle type of insects and the vibration characteristics of wing in the direct-flight-muscle type of insects. In the indirect-flight-muscle type of insects, the deflections of thoracic exoskeleton are measured under the static load. As results, the obtained load-deflection diagrams show linear relation between them. In the direct-flight-muscle type of insects, the ultra high speed video camera is used to record the wing motion under the free flight conditions by making use of their nature of high sensitivity to light. The frequencies of wing vibration are determined from the analyses of recorded data on videotapes. It is found that the vibration frequencies depend on the wing mass in the case of losing weight and independent on it in the case of gaining weight.
