The Mechanism of Flight Preparation in Some Insects

Abstract

ABSTRACT In 1928 Dotterweich published under the title “Beitrâge zur Nervenphysiologie der Insekten” some very interesting and important observations and measurements mainly on Sphingidae, showing that the rapid vibration of the wings regularly observed in large moths before they take flight produces an increase in temperature of the wing muscles which is necessary to enable them to fly at all. The temperature reached was nearly the same in all cases, 32-34° C., and the time taken to reach it varied with the initial temperature deficit, up to 6 min. with a deficit of 23°. Moths kept at 34° or above would fly off at once, without any preparation, when stimulated. It had been assumed by v. Buddenbrock that this preparation was mainly required to attain the high frequency of the wing movements necessary for actual flight, but a number of observations made by Dotterweich on butterflies (Vanessa), in which the normal frequency is much lower, made it very probable that in these also preparatory wing movements were responsible for a rise in temperature necessary for actual flight.