Tethered insect flight: A system for automated data processing of behavioral events

Flight mills to which flying insects are tethered, and which allow measurement of locomotion in a circular path, are used to measure flight capability in terms of frequency, duration, velocity, and distance. Also, they are adaptable to measurement of physiological processes such as respiration and energy consumption. We describe a flight-mill system with floating magnets and Teflon® bearings in its rotor that minimize frictional drag. Rotation (of the mill rotor) is transduced by interruption of a light beam to a phototransistor, which produces a signal monitored by a specially constructed event recorder. The event recorder temporarily stores the data from each mill and then transmits them in proper format for permanent storage on seven-track magnetic tape. The system allows simultaneous data collection from 18 individual insects and provides a computerized interpretation of their performance. The result is an analysis of all the significant parameters of flight that can be derived by measuring duration, velocity, distance, and frequency.