A Roundabout for Studying Sustained Flight of Locusts

Abstract

A roundabout technique is described which makes it possible to study the flight performance of a small ‘swarm’ of locusts (up to thirty-two individuals) for hours at a time. The resistance of the roundabout was compensated by means of a mill so that the locusts only had to overcome their own air resistance. The speed of the revolving periphery therefore equalled the preferred average flying speed of the suspended locusts. The average speed during a period, as well as the variation in speed in the course of an experiment, were found to be the same in the roundabout and in experiments where single locusts flew in front of a wind tunnel. In the latter case the insects flew in completely normal flight posture. It was concluded that the results obtained with the roundabout were as valid as the results obtained with a wind tunnel. Some preliminary results are given on the influence of different external factors on the flying speed and the ability to endure sustained flight.