A portable system for monitoring the behavioral activity of Drosophila

► We describe a novel measurement system for Drosophila behavior and activity. ► Multiple individuals can be monitored continuously and from different angles. ► Measures active period during walking or flying, and subtler movements related to wing or leg position. ► System use demonstrated with behavioral responses to known environmental stressors. ► Can be modified for use with other moving animals/objects. We describe a low-cost system for monitoring the behavioral activity of the fruit fly, Drosophila melanogaster. The system is readily adaptable to one or more cameras for simultaneous recordings of behavior from different angles and can be used for monitoring multiple individuals in a population at the same time. Signal processing allows discriminating between active and inactive periods during locomotion or flying, and quantification of subtler movements related to changes in position of the wings or legs. The recordings can be taken continuously over long periods of time and can thus provide information about the dynamics of a population. The system was used to monitor responses to caffeine, changes in temperature and g-force, and activity in a variable size population.