The Predatory Response of Chaoborus Larvae to Acoustic Stimuli, and the Acoustic Characteristics of their Prey

A quantitative study of the relationship between attack behaviour and the distance of the source of an underwater acoustic signal (a vibrating probe) is undertaken for the larvae of a phantom midge. Attack distance was affected by the probe frequency and amplitude, and by the level of hunger of the larva. The acoustic signals from natural prey are also analyzed, and their frequency characteristics compared with the probe frequencies most effective at releasing attack behaviour.